time

Question 1

what is the difference between periodic and interval timing

Answer 1

• periodic - learning to respond at a specific time of day
• interval - learning to respond at a specific interval of time

Question 2

what is entrainment

Answer 2

• the process where lights act as a zeitgeber to synchronise the internal biological clock with the actual day-night cycle

Question 3

what did roberts observe in cockroaches regarding their internal clock

Answer 3

in constant dim light, their activity drifted to slightly less than 24 hours, starting about 15 hours before dusk

Question 4

according to bolles and stokes, is the 24 hour clock innate or learned

Answer 4

it appears innate
- rats raised on 19- or 29-hour cycles still only successfully learned to anticipate food on a 24 hour cycle

Question 5

what brain structure is considered the central timekeeper for periodic timing

Answer 5

the suprachiasmatic nucleus of the hypothalamus

Question 6

what happens to animals if the SCN is lesioned

Answer 6

it abolishes the circadian regularity of foraging and sleeping

Question 7

how is the SCN relevant to cancer treatment

Answer 7

through chronotherapy, clock genes governed by the SCN control cell cycles and drug-breaking enzymes, meaning tumours have varying sensitivity to chemotherapy depending on the time of the day

Question 8

what is the peak procedure used to measure

Answer 8

it measures interval timing by seeing when an animal’s response rate peals when a reward is expected but omitted

Question 9

define weber’s law in the context of time

Answer 9

the ‘just noticeable difference’ is proportional to the initial magnitude
- this means small time intervals are judged more accurately in absolute terms than large ones

Question 10

what are the three main components of scalar timing theory

Answer 10

• pacemaker - emits pulses at a constant rate
• memory - stores the number of pulses
• comparator - current pulses stored values to decide if it’s time to respond

Question 11

in scalar timing what does the k value in reference to memory represent

Answer 11

• if k=1, memory is accurate; if k doesn’t = 1 , a different number of pulses is stored, reflecting that error is proportional to duration

Question 12

how does the comparator decide to respond

Answer 12

it uses a ration rule - currentpulses - storedpulses / storedpulses
- if the resulting value is small, the animal responds

Question 13

what are the 2 major criticisms of scalar timing theory

Answer 13

• there is no physiological evidence yet for a pacemaker
• conditioning and timing are treated as separate mechanisms even though they happen simultaneously

Question 14

what is behavioural theory of timing

Answer 14

• suggests timing is achieved by the animal moving through an invariant series of behaviours
• the behaviour occurring at the time of reinforcement becomes the signal for that reward

Question 15

how do real time models explain timing

Answer 15

they assume stimulus changes over the course of it’s presentation (a stimulus race), allowing the animal to learn exactly when a reinforcer occurs through regular conditioning mechanisms