Peer mentoring Flashcards

Question

where is body temperature controlled?

Answer 1

brain stem

Answer 2

hierarchical

Answer 3

primary visual/auditory/sensory motor areas -> second sensory areas -> association areas

Answer 4

- neurosurgery - stroke - brain trauma - neurodegeneration - infection

Answer 5

examines the effects of brain damage on cognitive abilities and behaviour

Answer 6

Paul Broca in the 19th century

Answer 7

Sperry and Gazzaniga

Answer 8

callosotomy

Answer 9

putting one hemisphere to sleep and seeing hwo it responds to stuff (e.g. holding a spoon)

Answer 10

the brain doesnt recognise an area of space

Answer 11

brenda milner with HM

Answer 12

classic (localisation) and cogntiive (determine cognitive architecture)

Answer 13

the logic of dissociation

Answer 14

micro-electrode recordings and EEG

Answer 15

* The most direct and precise measure of brain activity * However, because it is invasive, its use is very restricted both in terms of the subjects available and brain areas that can be investigated in patients * High temporal resolution as it measures spikes and post-synaptic potentials * High spatial resolution as it measures activity at the source

Answer 16

•Non-invasive •High temporal resolution > it measures fast electrical processes (post-synaptic potentials) •Low spatial resolution > the location of activity is difficult to infer

Answer 17

- the spatial extent of action potentials is too small and the time too short for them to be reflected in the EEG - of the shape of the electrical fields they elicit

Answer 18

D) being highly invasive

Answer 19

A) being highly invasive

Answer 20

Gradual slowing i.e. Lower frequencies

Answer 21

Rapid Eye Movement sleep. EEG frequencies are very fast. During REM most vividly recalled dreams are believed to occur

Answer 22

Greater cortical activity

Answer 23

THe motor cortex

Answer 24

EEG is cheaper and more portable - it can easily be deployed to the patient's bedside

Answer 25

E) verbal response

Answer 26

3/16 patients activated areas of the motor cortex according to the instructions

Answer 27

Abnormal/Excessive synchronisation of post-synaptic potentials, resulting in large amplitude discharges.

Answer 28

during seizures

Answer 29

between seizures

Answer 30

C) separately averaged

Answer 31

stimulus onset asynchrony

Answer 32

Psychological Refractory Period – Present 2 tasks in rapid succession. E.g. Tone discrimination or Word Relatedness.

Answer 33

Processing in Task 1 interferes with the processing of the target meaning in task 2. SO… it suggests that meaning is not accessed automatically.

Answer 34

the amount of time between stimulus 1 and stimulus 2

Answer 35

Inferring cortical generators from known scalp potentials. This is highly uncertain. There is an infinity of cortical current distributions that could result in one scalp distribution.

Answer 36

Epileptic EEG distribution on scalp Localisation based on EEG source estimation Localisation by correlation with concurrently acquired fmri data

Answer 37

c) good spatial resolution

Answer 38

c) good termporal resolution

Answer 39

- highly invasive: require surgery - high temporal resolution: measure spikes and post-synaptic potentials - high spatial resolution: measure activity at the source

Answer 40

- non-invasive (innocuous) - measures post-synaptic potentials - high temporal resolution, sicne it measures fast electrical processes - low spatial resolution location of activity; difficult to infer

Answer 41

- moderatly invasive: radioactivity is introduced into the body - measures indirect metabolic correlates of neural activity (e.g. blood, glucose) - can measure synaptic transmission (e.g. labelling receptors) - relatively high spatial resolution precision - low temporal resolution because it measures slow processes

Answer 42

- non0invasive (innocuous) - measures indirect metabolic correlates of neural activity (e.g. blood) - high spatial resolution (highest among all techniques) - low temporal resolution, because it measures slow processes

Answer 43

1. electric synapse: gap junctions connecting the cytoplasm of two neurons 2. Chemical synapse: Signal transmission within a spiking neuron

Answer 44

A. Instantaneous current flow > very fast transmission of electric signal across connexons, producing virtually no time delays B. They are found where fast responses and/or synchronisation of activity is required. > Fast action: Commanding escape responses (crayfish, fish) > Synchronised activity: Inhibitory neurons in mammalian brain, eye-moving muscles

Answer 45

A. Resting potential > Membrane potential when the neuron is at rest (=no signal transmission) B. Depolarisation > Graded potential before reaching threshold (-55mV) when the neuron is excited (received signal) C. Action potential > Spikes are generated in the integration zone of a neuron if depolarisation reaches threshold (-55mV). > Signal transmission inside neuron. D. Signal transmission to next neuron > It starts when action potentials reach in the output zone of a neuron.

Answer 46

It consist of three subunits, influencing adjacent ion channels. When activated by a conformational change, G protein can interact directly with ion channels or control the release of another messenger molecule inside the postsynaptic cell.

Answer 47

D) regular channels

Answer 48

Long neurons with thicker axons - found in squids, and invertebrates. Myelinisation of axons (Schwann cells) - mostly in vertebrates

Answer 49

Cells that assist the signal propagation (Schwann cells) and provide nutrients to neurons.

Answer 50

The neural membrane is exposed at the nodes of Ranvier for ion conductance through voltage-gated channels for Saltatory conduction.

Answer 51

1. Type of neurotransmitter | 2. Duration of neurotransmitter release

Answer 52

If the neurotransmitter is released for longer time into the synaptic cleft, then the postsynaptic potential is stronger.

Answer 53

If postsynaptic potentials, fired from two different neurons, arrive together in the integration zone, they are summed up.

Answer 54

depolarisation

Answer 55

hyperpolarisation

Answer 56

glutamate, aspartate, nicotinic

Answer 57

GABA, glycine, muscarinic acetylcholine.

Answer 58

if the membrane at the integration zone is depolarised above a threshold, an action potential will be generated.

Answer 59

the stronger the output signal.

Answer 60

the weaker the output signal/the neuron may not even fire.

Answer 61

An action potential will be generated

Answer 62

An action potential will not be generated, so the signal is not transmitted.

Answer 63

HE SUM OF THE RELATIVE STRENGTHS OF EPSPs AND IPSPs THAT ARRIVE AT THE INTEGRATION ZONE TOGETHER WITHIN A GIVEN TIME WINDOW.

Answer 64

1. spatial/temporal summation 2. feedforward circuits 3. feedback loop

Answer 65

determine the strength of the signal when it is passed on from one neuron to the next.

Answer 66

distribute the signal to many neurons through divergence of their connections, or is determined by collecting signals from many neurons through convergence.

Answer 67

(positive/negative) provide direct or indirect input influencing signals and thus information.

Answer 68

The observer defines the start and end.

Answer 69

No, but there could be some small bosses or gatekeepers, as proposed by the grandmother cell/agnostic cell hypotheses.

Answer 70

No, they can branch out into parallel streams, have feedback loops, share neurons with other networks, and change over time.

Answer 71

a. nicotinic acetylcholine

Answer 72

b. Myelination causes the problem of signal loss.

Answer 73

Skill learning Conditioning Priming

Answer 74

``` Semantic memory (facts) Episodic (what, when, where) ```

Answer 75

The site of contact between neurons(synapse) plays a role in memory formation. Hebbian theory claims that an increase in synaptic efficiency comes from a presynaptic repeated stimulation of the postsynaptic cell.

Answer 76

1. Cell A repeatedly excites cell b 2. This causes a metabolic change 3. A’s efficiency at firing B is increased

Answer 77

1. Temporal Filtering: change in selectivity for the frequency range of spikes arriving in the axon terminal 2. Gain Control: change in the amount of neurotransmitter released for a given signal 3. Presynaptic facilitation or depression

Answer 78

This a form of synaptic plasticity studied in Aplysia. The withdrawal reflex is mediated by sensory neurons that synapse to the motor neurons After repeated stimulation over an hour, habituation occurs because the sensory neurons release less neurotransmitter to the motor neurons If this process carries on over several days, there is a long term habituation caused by a retraction of some synaptic terminals from the sensory to motor neurons

Answer 79

b. Sound (CS) preceding food (US)

Answer 80

ANSWER: BIGGER London taxi drivers hippocampi is larger than bus drivers. - Greater grey matter volume in the mid-posterior hippocampi - Less volume in anterior hippocampi

Answer 81

- Mossy fibre pathway (dentate gyrus to CA3 pyramidal cells). - Perforant pathway (input from entorhinal cortex) - Schaffer collateral pathway (CA3 to CA1 pyramidal cells)

Answer 82

1. AMPA receptors a. Ionotropc (ligand-gated ion chanels) b. Open if glutamate binds to them → Na+ flow into postsynaptic neuron c. EXCITATORY - Na+ influx depolarises EPSPs 2. NMDA receptors a. Ligand and voltage gated b. Cell resting = blocked by Mg2+ c. Binding glutamate is necessary but alone insufficient to open them

Answer 83

Binding of glutamate | Membrane depolarises above the threshold expelling the Mg2+ plug

Answer 84

YES - Increasing evidence from various studies suggest this.

Answer 85

A) re-uptake

Answer 86

- Some act as early as the propagation of the action potential - Others may influence the release of the transmitter - Others modulate how the transmitter interacts with the post-synaptic channels (receptors) - Finally, some alter the presence of the transmitter in the synapse by modulating its inactivation and recycling

Answer 87

C) tetrodotoxin

Answer 88

Tetanospasmin, which interferes with the vesicles of the neurotransmitter GABA fusing with the cell membrane. This reduces the amount of GABA released into the synapse. Botulinum toxin interferes with the release of Acetylcholine at nicotinic synapses, by preventing the vesicles from fusing with the cell membrane Amphetamine facilitates the release of dopamine from the vesicles when these fuse with the membrane

Answer 89

B) False interacts with excitatory synapses

Answer 90

Imitates the behaviour of the neurotransmitter (NT)... INCREASING its effect.

Answer 91

→ HEROIN; artificially modified form of morphine (opium). → It is an AGONIST of ENDORPHINS. Natural body chemicals that bind to OPIATE RECEPTORS and reduces pain and induces relaxation.

Answer 92

Marijuana (Cannabis) → Contains THC. Agonist of Anandamide; Natural body chemical which binds to CANNABINOID RECEPTORS. Involved in emotion, pain, appetite and memory. Tobacco (Nicotine) → Stimulates NICOTINIC RECEPTORS. Agonist for ACETYLCHOLINE. (ACh) Short-live generalised excitatory effect, e.g.. Increases blood adrenaline level.

Answer 93

1.Diffusion: Transmitter is lost in the inter-cellular space 2. Enzymatic Degradation: Enzymes break down the transmitter. 3. Re-Uptake (uptake): Transmitter is recycled either in pre or post-synaptic neuron. This is the most economical way to inactivate the transmitter as it saves synthesis resources

Answer 94

Because anandamide (agonist = THC) and phenylethylamine (related to amphetamine) are not found in amounts considered to have a substantial effect.

Answer 95

Prozac/Fluoxetine is used for the treatment of depression. It is an SSRI (Selective Serotonin Reuptake Inhibitor). It works by inhibiting the absorption of serotonin via the serotonin transporter without affecting other monoamines (e.g. dopamine). Other treatment drugs for depression are MAO inhibitors and Tricyclic antidepressants.

Answer 96

GABA agonists used to treat anxiety disorders (characterised by deficits in GABA-ergic transmission). They do not bind to the same receptor as GABA itself, therefore, are a non-competitive agonist. Beta Blockers such as propranolol can also be used to treat anxiety disorders as they address the physiological symptoms such as increased heart rate. SSRI’s are also commonly prescribed for anxiety.

Answer 97

Neuroleptics such as Haldol are anti-psychotic drugs used to treat schizophrenia and other psychotic disorders (e.g. bipolar and major depressive disorder). They block the transmission of dopamine by binding to dopamine receptors without opening ion channels (they are antagonists). Atypical Antipsychotics such as Quetiapine (seroquel) are also used.

Answer 98

Cocaine blocks the transporter of noradrenaline and dopamine, thus interfering with their re-uptake and boosting their effect. The overall effect is a boost in monoamine transmission (dopamine, noradrenaline, serotonin). Increasing monoaminergic (especially dopaminergic) transmission can induce schizophrenia-like symptoms. Hence why you feel elation after ingesting the substance. It is important to note use of these drugs can elicit a psychotic ‘break’.

Answer 99

Inhibiting from doing something.

Answer 100

Stimulating a reaction.

Answer 101

blocks the binding of naturally occurring neurotransmitters.

Answer 102

stimulates action potential.

Answer 103

Antagonist (Inhibits) – binds to post-synaptic receptors and blocks the binding of naturally occurring neurotransmitters. Agonist (Stimulates/Imitates) – Binds to post-synaptic receptors and stimulates action potential. Example: GABA + Alcohol. In low doses alcohol acts as an agonist and in high doses acts as an antagonist. In very high doses alcohol destroys cell membranes and causes brain death.

Answer 104

- Improved Social interaction - Facilitated sexual behaviour - Improved cognitive performance and counteracting fatigue - Facilitated recovery from and coping with psychological stress - Self-medication for mental problems - Sensory curiosity - Expanded perception horizon - Euphoria, hedonia, and high - Improved physical appearance and attractiveness

Answer 105

Cocaine addiction is associated with brain damage risks, appearing minutes/hours after consumption E.g. Seizures, early strokes, and lesions resulting in movement disorders Along with reduced volume of the inferior portion of the frontal lobe

Answer 106

A reduction in grey matter (e.g. in the frontal temporal regions A reduction in white matter (spongiform leukoencephalopathy) Brain hypoxia (reduced oxygen availability Stroke (loss of blood supply) Cerebral edema (water saturation) Myelopathy (paralysis produced by spinal lesions)

Answer 107

Alcoholism is linked to Wernicke-Korsakoff syndrome Wernicke’s encephalopathy -> brain shrinkage - Characterised by changes in mental state and inability to concentrate, apathy. - Korsakoff syndrome is characterised by anterograde amnesia, language problems and difficulty with movement. - Korsakoff syndrome can sometimes be treated with thiamine supplements.

Answer 108

Cannabis use is associated with a reduction in brain volume, especially in the hippocampus and the amygdala

Answer 109

Longitudinal research shows that cannabis use is associated with development of psychotic symptoms

Answer 110

1. Effects of drug-related cues - cue reactivity 2. Effects of drug tolerance and withdrawal 3. Drugs influences on processing of rewards and incentives (pleasure & motivation) 4. Self medication

Answer 111

reduced reaction to the same dose of a drug after repeated use.

Answer 112

symptoms which appear when stopping or reducing drug intake after having developed drug dependence, for example: sweating, fatigue, vomiting, insomnia, irritability and shaking.

Answer 113

homeostatic protection, reducing the potentially harmful effects of the drug •e.g. by raising heart rate in heroin addicts but can lead to overdose

Answer 114

Involves activation of the VTA or Nucleus Accumbens (situated in the Basal Ganglia)

Answer 115

Administration of a dopamine antagonist (PIMOZIDE) increases lever pressing, even WITHOUT REINFORCEMENT…

Answer 116

* Dopaminergic circuit involving NA (nucleus accumbens) and VTA (ventral tegmentum area) is responsible for the motivation to obtain a drug, not the pleasure obtained from it. * Sensitisation to drugs occurs because addicts drug use strongly potentiates (increases the power of) the motivation-related dopaminergic synapses in the brain, with repeated use of the drug leading to greater responses in the dopamine circuit, independently from the effects of the drug on euphoria. * Differs from Anhedonia hypotheses as… * Anhedonia hypotheses relates to PLEASURE (reward). * Incentive salience theory relates to MOTIVATION (incentive).

Answer 117

1.Drug use could cause mental illness through neurotoxicity. •Substantial evidence that drug use causes mental illness (see earlier slide on cannabis and psychosis) 2.Mental illness could cause drug dependence through self-medication. •E.g. McKee et al. (2011); Moeller et al. (2001). 3.Both causal mechanisms might exist and be reciprocal.

Answer 118

The number and frequency of action potentials and the number of muscle fibers determine the force the muscle can generate.

Answer 119

somatotopic organisation (aka map of the body), lesions lead to hemiplegia, loss of voluntary movement to contralesional side of body AKA if the left hemisphere is damaged, right side of body is affected)

Answer 120

planning and control of movement, lesions cause apraxia (inability to link simple gestures into meaningful actions)

Answer 121

represents space, attention and sensorimotor integration, very complex functions. Lesions cause apraxia but also problems with attention, specifically spatial attention (aka neglect)

Answer 122

neurons are able to hold a representation of the entire pattern movements required to produce a complex motor act (refer to Brown and Sherrington, 1947) Sheds light on hierarchical system … If higher level neurons in the brain don’t represent specific action plans, what do they do?

Answer 123

aNSWER: B Evidence from Bizzi et al. (1984) Severed somatosensory signals in monkeys, trained to reach target Opposing force applied to arm (starting position) Monkeys still able to reach for target as before (neurons in cortical motor regions represent movements by encoding the end-point location)

Answer 124

ANSWER: they prefer a range of directions

Answer 125

direction of cell’s preferred direction combined with info about strength of firing (hard to predict direction of movement)

Answer 126

sum of individual neuron vectors (easier to predict direction of movement)

Answer 127

1. Actual movement trajectory VS Observed movement trajectory 2. Effects of transcranial direct current stimulation (tDCS) on visuomotor adaptation: dissociation between cerebellum and M1 (primary motor cortex) 3. Effect of transcranial magnetic stimulation of the cerebellum on forward models

Answer 128

The hands of the subjects were hidden and mismatch, between where they moved their hand and where they saw it moving, was created. They later adapted their movements to this mismatch. Increased activation was also shown across many different motor regions during the adaptation phase. Patients with lesions in areas involved in motor control, including cerebellum, prefrontal cortex and parietal cortex have deficits in learning to move in novel environments. This suggests that motor regions are critical.

Answer 129

excitability of neurons under the electrode.

Answer 130

faster rate of adapation

Answer 131

increased retention of adaptation (more error for a longer period of time after the end of adaptation).

Answer 132

Subjects moved their arm to the right. When a tone occurred, they made a movement to a visual target. A prediction of where your hand would be in the future was required, because there was a delay, between hearing the tone and actually initiating the forward movement. If the subject just generated a motor command when they heard the tone, they would miss the target since the motor command trajectory would be out of date and inaccurate by the time the motor command was actually initiated. The subjects were pretty accurate in the experiment. Average directional errors in the TMS condition were consistent with reaching movements being planned and initiated from an estimated hand position that was 138 ms out of date. The results show that the forward models generated by cerebellum uses information about future position of limb to compute the trajectory required to hit the target.

Answer 133

- Basal ganglia play a key role in movement initiation - Pathways are mutually antagonistic: - Direct pathway leads to increased excitation (Movement initiation) - Indirect pathway leads to increased inhibition (Movement inhibition) This enables the system to achieve a balance: - Activation of the direct pathway can lead to too much movement, which can be balanced out by inhibitory activation of the indirect pathway.

Answer 134

Loss of dopamine neurons in the basal ganglia

Answer 135

Reduction in voluntary movement (Hypokinesia) Slow movement (Bradykinesia) Tremor

Answer 136

1. Levodopa (‘L-dopa’) is a dopamine precursor, which crosses the blood-brain barrier and enters the CNS, converting into dopamine 2. Deep Brain Stimulation (DBS)

Answer 137

- Subjects are trained to press left for red things and squares and right for green things and triangles. Then in the test phase they see pairs of stimuli and have to press left or right – told to respond to either the colour or the shape. On some trials, they respond to the same dimension and on others it switches. - Patients with Parkinson’s Disease were particularly impaired on switching trials. Basal ganglia appears to play a dual role in action and cognition, allowing new thoughts and new movements to occur. This highlights the strong links between the cognitive and motor systems.

Answer 138

c) Cerebellum is involved in learning new mapping by generating forward models while M1 is important for consolidating newly learnt mapping.

Answer 139

a) It has no role.

Answer 140

``` Mechanical e.g. touch, pain Visual Thermal (decreases and increases in skin temperature) Chemical e.g. smell and taste Electrical ```

Answer 141

structures that contain receptors and interneurons that are specialised for detecting and processing certain types of stimuli

Answer 142

- specialized to detect internal and external stimuli of a sensory modality and to act as a filter for stimulus information. - They transform stimulus energy into neural signals, which are transmitted to the sensory interneurons

Answer 143

If all neurons share the same vocabulary of neural signals, how does the brain know which receptor responded to a stimulus so modality can be determined?

Answer 144

which axons convey the signals (principle of sensory labelled lines).

Answer 145

Different qualities of skin stimulation can be communicated to distinct areas in the brain

Answer 146

The region in space in which stimuli affect that neurons firing rate

Answer 147

Merkel's disc and Meissner's corpuscle They are sensitive to stimuli in small areas of the skin

Answer 148

Example: Pacinian corpuscles and Ruffini’s endings In deeper layers, sensitive over a larger area of skin

Answer 149

slow loss of response

Answer 150

fast loss of response

Answer 151

in the postcentral gyrus in the parietal lobe of the human brain. Brodman areas 1,2 and 3a,b

Answer 152

1. often suppression involves accessory organs. SUch structures reduce the intensity or alter the stimulus before it reaches the receptor (e.g. eyelids, muscles) 2. or it can be via top-down processes. e.g. brain stem sends messges to receptor cells in the eat to selectively dampen sounds

Answer 153

d. A receptor with a slow loss of response

Answer 154

c. Both, if stimulus intensity is high | d. B, if stimulus intensity is low

Answer 155

Differences in wavelenth and intensity

Answer 156

Eyes evolved through a sequence of improvements for detecting directions and forming an image Advanced types of eyes have evolved several times in the animal kingdom Fossils dating back to the Cambrian explosion Daster movement and navigation in animals required better vision

Answer 157

b) Suprachiasmatic Nucleas

Answer 158

c. Circadian rhythms

Answer 159

Unpaired midline structure near the epithalamus | Produces melatonin during darkness

Answer 160

A → The central portion of the retina. This is where the highest density of photoreceptors are… SO, it is the center of our gaze.

Answer 161

→ Used a head mounted eye movement video camera. → A white dot indicated foveal direction. A second camera recorded what the person did. → Foveal direction was always close to the object being manipulated, very few fixations were irrelevant to the task. → Roughly 1/3rd of fixations on objects were; locating objects for later use, directing the hand to a new location, guiding e.g., kettle and lid, and checking variable state e.g., water level. SO… although tea-making is automated, the eyes closely monitor every step of the way. This is unconscious attention.

Answer 162

yes and no

Answer 163

Smooth pursiut movements, saccades, optokynetic nystagmus, vestibulo-occular movements.

Answer 164

Rapid eye movements to a new position between fixations. Why? To scan the scene.

Answer 165

Slow, keeps a moving stimulus on the fovea.

Answer 166

Brings the eye back from peripheral (side) to a central position after following a large-scale moving stimulus (whilst head is still).

Answer 167

Compensate for head movement, done by moving the eye the same distance but in the opposite direction. Why? Maintain a constant field of view

Answer 168

superior colliculus

Answer 169

cortical frontal eye fields

Answer 170

95 million

Answer 171

Specialised for high sensitivity to see in DIM light.

Answer 172

Specialised for high acuity and high speed of response to see in BRIGHT light

Answer 173

false Sharpness of vision is highest in the fovea, and decreases towards the periphery. At night, sharpness is sacrificed for sensitivity so it is more advantageous to have no rods in the fovea.

Answer 174

A: 1 A: Rhodopsin (RH1)

Answer 175

Transducin

Answer 176

The membrane becomes MORE polarised.

Answer 177

A: Geniculate-striate pathway and the Extrageniculate pathway

Answer 178

Retina - LGN - V1 - higher visual cortex

Answer 179

d. Meaningless VS Meaningful

Answer 180

b. Lateral inhibition occurs where the neurons are interconnected. As they tend to inhibit their neighbours, the photoreceptors report receiving less light than they actually do on the right edge (i.e. that edge looks darker to us)

Answer 181

C) Horizontal and amacrine cells

Answer 182

``` Fovea = 1 cone to 1 bipolar cell Periphery = many cones to 1 bipolar cell, many bipolar cells to 1 ganglion cell ```

Answer 183

Center-surround RF

Answer 184

ON-center and OFF-centre

Answer 185

c. glutamate

Answer 186

Movement of light spots

Answer 187

B) Rate the cell fires action potentials (spikes) increases

Answer 188

when light spot on center increases

Answer 189

when light spot on center increases

Answer 190

Fires at spontaneous rate (at rest)

Answer 191

All neurons in an orientation column share the same preference for a particular orientation of a bar stimulus in their receptive field Retinotopic organisation: Signals from co-located ganglion cells in the retina are processed by respectively co-located cortical neurons within each orientation column Hubel and Wiesel (Harvard, USA) were awarded the Nobel prize in 1981 for their work in the 60s and 70s

Answer 192

Hubel and Wiesel proposed that simple cells in the orientation columns receive input from several neighbouring retinal ganglion cells.

Answer 193

From retinal image to 3D model in the cortex

Answer 194

The number of light/dark (or color) cycles that the stimulus shows per degree of visual space.

Answer 195

Simple cortical cells (aka bar detectors or edge detectors): respond best to an edge or a bar of particular width, orientation, and location in the visual field. Complex cortical cells: respond best to a bad or particular size and orientation anywhere within a particular area of the visual field.

Answer 196

a. Analysis of contours and boundaries analysis of objects b. Shape and positional invariance c. Contour enhancement for object identification d. All of the above

Answer 197

We recognise the same shape from different viewpoints and directions despite the distortions in the retinal projections.

Answer 198

When objects are at different distances, the size of their retinal projection varies. Context information allows the brain to judge whether the same object is seen from a different distance or a different object is seen.

Answer 199

Dorsal stream - where system, interacting with the world. Ventral stream - what system, making sense of the world.

Answer 200

where system, interacting with the world.

Answer 201

what system, making sense of the world.

Answer 202

Making sense of the world

Answer 203

Differences in wavelenth and intensity

Answer 204

Eyes evolved through a sequence of improvements for detecting directions and forming an image Advanced types of eyes have evolved several times in the animal kingdom Fossils dating back to the Cambrian explosion Daster movement and navigation in animals required better vision

Answer 205

b) Suprachiasmatic Nucleas

Answer 206

c. Circadian rhythms

Answer 207

Unpaired midline structure near the epithalamus | Produces melatonin during darkness

Answer 208

A → The central portion of the retina. This is where the highest density of photoreceptors are… SO, it is the center of our gaze.

Answer 209

→ Used a head mounted eye movement video camera. → A white dot indicated foveal direction. A second camera recorded what the person did. → Foveal direction was always close to the object being manipulated, very few fixations were irrelevant to the task. → Roughly 1/3rd of fixations on objects were; locating objects for later use, directing the hand to a new location, guiding e.g., kettle and lid, and checking variable state e.g., water level. SO… although tea-making is automated, the eyes closely monitor every step of the way. This is unconscious attention.

Answer 210

yes and no

Answer 211

Smooth pursiut movements, saccades, optokynetic nystagmus, vestibulo-occular movements.

Answer 212

Rapid eye movements to a new position between fixations. Why? To scan the scene.

Answer 213

Slow, keeps a moving stimulus on the fovea.

Answer 214

Brings the eye back from peripheral (side) to a central position after following a large-scale moving stimulus (whilst head is still).

Answer 215

Compensate for head movement, done by moving the eye the same distance but in the opposite direction. Why? Maintain a constant field of view

Answer 216

superior colliculus

Answer 217

cortical frontal eye fields

Answer 218

95 million

Answer 219

Specialised for high sensitivity to see in DIM light.

Answer 220

Specialised for high acuity and high speed of response to see in BRIGHT light

Answer 221

false Sharpness of vision is highest in the fovea, and decreases towards the periphery. At night, sharpness is sacrificed for sensitivity so it is more advantageous to have no rods in the fovea.

Answer 222

A: 1 A: Rhodopsin (RH1)

Answer 223

Transducin

Answer 224

The membrane becomes MORE polarised.

Answer 225

A: Geniculate-striate pathway and the Extrageniculate pathway

Answer 226

Retina - LGN - V1 - higher visual cortex

Answer 227

d. Meaningless VS Meaningful

Answer 228

b. Lateral inhibition occurs where the neurons are interconnected. As they tend to inhibit their neighbours, the photoreceptors report receiving less light than they actually do on the right edge (i.e. that edge looks darker to us)

Answer 229

C) Horizontal and amacrine cells

Answer 230

``` Fovea = 1 cone to 1 bipolar cell Periphery = many cones to 1 bipolar cell, many bipolar cells to 1 ganglion cell ```

Answer 231

Center-surround RF

Answer 232

ON-center and OFF-centre

Answer 233

c. glutamate

Answer 234

Movement of light spots

Answer 235

B) Rate the cell fires action potentials (spikes) increases

Answer 236

when light spot on center increases

Answer 237

when light spot on center increases

Answer 238

Fires at spontaneous rate (at rest)

Answer 239

All neurons in an orientation column share the same preference for a particular orientation of a bar stimulus in their receptive field Retinotopic organisation: Signals from co-located ganglion cells in the retina are processed by respectively co-located cortical neurons within each orientation column Hubel and Wiesel (Harvard, USA) were awarded the Nobel prize in 1981 for their work in the 60s and 70s

Answer 240

Hubel and Wiesel proposed that simple cells in the orientation columns receive input from several neighbouring retinal ganglion cells.

Answer 241

From retinal image to 3D model in the cortex

Answer 242

The number of light/dark (or color) cycles that the stimulus shows per degree of visual space.

Answer 243

Simple cortical cells (aka bar detectors or edge detectors): respond best to an edge or a bar of particular width, orientation, and location in the visual field. Complex cortical cells: respond best to a bad or particular size and orientation anywhere within a particular area of the visual field.

Answer 244

a. Analysis of contours and boundaries analysis of objects b. Shape and positional invariance c. Contour enhancement for object identification d. All of the above

Answer 245

We recognise the same shape from different viewpoints and directions despite the distortions in the retinal projections.

Answer 246

When objects are at different distances, the size of their retinal projection varies. Context information allows the brain to judge whether the same object is seen from a different distance or a different object is seen.

Answer 247

Dorsal stream - where system, interacting with the world. Ventral stream - what system, making sense of the world.

Answer 248

where system, interacting with the world.

Answer 249

what system, making sense of the world.

Answer 250

Making sense of the world

Answer 251

P- colour | M- motion

Answer 252

It is reflected

Answer 253

It gets absorbed by eye media and water

Answer 254

Photospectrometer

Answer 255

Lens of the human eye absorbs UV and with increasing age also short wavelengths (violet, blue)

Answer 256

Dichromacy, trichromacy, tetrachromacy

Answer 257

X-chromosome recombination ●S-cone opsin gene on chromosome 7 ●M- and L-cone opsin genes on X chromosome

Answer 258

Severe colour-deficiency: (only two cone opsins expressed in retina), lacking cones ●Mild colour-deficiency: (one cone opsin is anomalous), mutated form of pigment – small shifts in the spectrum

Answer 259

Trichromatic vision is a result of gene duplication in primates (therefore close overlap of L- and M-cone spectral sensitivities), it is optimal to detect and distinguish ripe fruit

Answer 260

A lack of support. | B.Observations in natural habitats do not reveal yet any differences in behavioural profiles

Answer 261

The type of wavelength determines how the LGN ganglion cells respond, to some wavelengths they fire, and to others they are inhibited.

Answer 262

S/(L+M) (old, mammalian) | B.L/M (new, trichromatic primates)

Answer 263

Humans have trichromatic colour vision

Answer 264

With additive colour mixing we can create any colour visible to humans by mixing the three wavelengths corresponding to the peak sensitivities of the three types of cone receptors

Answer 265

Looking at an original colour contrast would cause you to perceive a contrast later which is not there

Answer 266

Colour constancy is the ability to recognise colours under different illuminations.

Answer 267

Tympanum | Vibrations travel from the tympanum to the middle ear where they are amplified

Answer 268

ANSWER: they are arranged tonotopically along the basilar membrane. High frequencies displace the basilar membrane at the base Low frequencies displace the basilar membrane at the apex

Answer 269

: inner and outer hair cells… these are non-spiking receptor cells and respond to mechanical stimulation (aka stretch ion channels) with depolarisation

Answer 270

Opens in channels

Answer 271

B) 4 2 are afferent (hair cells → bran) 2 are efferent (brain → hair cells)

Answer 272

glutamate, acetylcholine, GABA and dopamine

Answer 273

C) Superior olivary nucleus (bilateral input, 1st stage in CNS at which binaural effects are processed)

Answer 274

calculating differences in delay and intensity between two ears -Input reaches each ear at different times → determines how sound is perceived -Jeffress model - brain codes latency (time) difference between sound heard by left and right ears by coincidence detection

Answer 275

Endocrine communication is where chemicals are released into the bloodstream where the selectively affect distant organs

Answer 276

Bioregulators of the endocrine system

Answer 277

Protein (including peptides) , amine and steroid

Answer 278

Oxytocin,Vasopressin, prolactin, Insulin, glucagon, GH, thyroid-stimulating hormones, follicle-stimulating hormones, luteinizing hormones ●Releasing hormones e.g. CRH and GnRH

Answer 279

Epinephrine, norepinephrine, melatonin and thyroid hormones

Answer 280

They are smaller. They are simpler NOT more complex

Answer 281

False. They act rapidly (secs to mins)

Answer 282

A.Increasing (upregulating) or decreasing (downregulating) the number of receptors on cells

Answer 283

The alarm response

Answer 284

Temperature regulation

Answer 285

NONE OF THEM. They are all involved… Look out for this kind of question as your exam can have typos...human error applies to lecturers too

Answer 286

ANSWER: D) None of the above → STRUCTURE: Pineal gland (PG) → HORMONE: Melatonin (amine hormone)

Answer 287

ANSWER: Hamsters 1.Sense shorter nights 2.PG reduces nocturnal secretion of melatonin 3.Hypothalamus less sensitive to -ve feedback effects of gonadal steroids 4.More GnRH released 5.More gonadotropin released, gonads swell, READY TO BREED!!!!! → Opposite seen during autumn

Answer 288

Ghrelin (peptide hormone)

Answer 289

Before mealtimes and night

Answer 290

Ghrelin is lower before eating | But following eating, their ghrelin levels do not drop

Answer 291

Mammalian oestrous cycle

Answer 292

They asked women what t-shirt they were wearing and found that when at high risk of conception, they were more likely to wear pink or red shirts, compared to when they were at a low conception risk.

Answer 293

They recorded tip earnings by dancers in a lap-dancing club, and collected information on hormone contraception and menstrual cycles. The dancers got more tips when they were fertile, and tips were lower for those using the pill.

Answer 294

Parental: you look after your own young. | ●Alloparental: you look after the young of others.

Answer 295

Maternal behaviour is inhibited

Answer 296

They injected meerkats with either oxytocin or a saline solution and found increased: guarding, pup feeding, closeness to pups, and communal digging, and decreased aggression - compared to the saline solution group. But the effects only lasted around 30 minutes.

Answer 297

Rodents and meerkats given supplementary doses of oxytocin spend more time in contact with others ●Knocking out oxytocin gene of male mice renders them unable to recognise the scent of previously encountered female ●Infusing brain with oxytocin cures this amnesia

Answer 298

Oxytocin injections promote pair bonding in the Prairie Vole. ●The Meadow Vole with few Vasopressin Receptors does not have the same effect.

Answer 299

●Anxiety reduction ●Perceptual selectivity/ Social salience ●Affiliative motivation

Answer 300

Those who received oxytocin made transfers 17% higher than the control.

Answer 301

Generosity, sensitivity, trust

Answer 302

Oxytocin increases during an orgasm

Answer 303

``` Contentment ●Reductions in anxiety ●Calmness ●Security ●Indications of pair bonding ```

Answer 304

Sympatho-adrenergic system (SAS) Hypothalamic-pituitary-adrenal (HPA) axis ●These systems organise responses to harmful situations ●Involves BIDIRECTIONAL brain-body communication

Answer 305

1.Alarm reaction ●Stressor is perceived by the pituitary-adrenal system ●SAS prepares body for fight or flight ●HPA releases energy stores 2.Resistance Stage ●Body tries to reestablish homeostasis ●If stressor persists, stress hormones/arousal stays high 3.Exhaustion stage ●Prolonged stress leads to illness and exhaustion of resources and body defences

Answer 306

Increase in blood pressure, tachycardia and tachypnoea

Answer 307

Brainstem nuclei, vagal nerve, adrenal medulla

Answer 308

Releases adrenaline and noradrenaline into the blood

Answer 309

Redirects blood to essential organs, increases blood pressure

Answer 310

Stimulates the adrenal cortex to release cortisol and other steroids This engages slower, passive coping mechanisms for when fight or flight is ineffective.

Answer 311

Stress is negative

Peer mentoring Flashcards

(354 cards)