Define a “divided-attention.” Give an original example of a divided-attention task. Define “selective attention.” What is a dichotic listening task? Briefly summarize the findings from studies of dichotic listening. How are these findings related to the cocktail party effect?
Divided attention is the ability to allocate attention to multiple tasks simultaneously, though performance usually declines as task demands increase; for example, texting while listening to a lecture. Selective attention is focusing on one stimulus while ignoring competing stimuli. A dichotic listening task presents different auditory messages to each ear through headphones.
Studies show people can report little about the unattended message but notice salient information like their name or emotional words. This relates to the cocktail party effect, where individuals focus on one conversation yet still detect personally meaningful information from unattended channels, showing that some unattended input is processed for significance.
Describe the Stroop effect, and explain how it is related to selective attention. What is the emotional Stroop task, and how has it been used?
Comment: The Stroop task can also be used to illustrate the role of inhibition. According to Matlin and Farmer, selective attending to colour is difficult when the competing stimuli can be processed automatically. An alternative explanation is that the automatically processed stimuli cannot be easily inhibited. As mentioned earlier, inhibition is an important complementary concept in selective attention. A useful metaphor to understanding the importance of inhibition is to consider the mechanisms that enable a car to move from place to place. In the same sense, a mental operation moves from one place to another. In a car, the gas pedal moves the car forward, and the brake stops the car when it reaches its destination. In the same way, activation starts a mental process toward a goal, and inhibition stops the mental process when it reaches its destination.
The Stroop effect occurs when naming the ink colour of a word is slowed if the word itself names a conflicting colour, demonstrating difficulty ignoring automatic reading. It reflects selective attention because attention must focus on ink colour while suppressing the more automatic word-reading process. The emotional Stroop task uses emotionally charged words to measure attentional bias and has been used to study anxiety, trauma, and phobias.
Comment: The Stroop task can also be used to illustrate the role of inhibition. According to Matlin and Farmer, selective attending to colour is difficult when the competing stimuli can be processed automatically. An alternative explanation is that the automatically processed stimuli cannot be easily inhibited. As mentioned earlier, inhibition is an important complementary concept in selective attention. A useful metaphor to understanding the importance of inhibition is to consider the mechanisms that enable a car to move from place to place. In the same sense, a mental operation moves from one place to another. In a car, the gas pedal moves the car forward, and the brake stops the car when it reaches its destination. In the same way, activation starts a mental process toward a goal, and inhibition stops the mental process when it reaches its destination.
Do Demonstration 3.1 and 3.2. How do these demonstrations illustrate the role of selective attention in visual search? Describe the two effects reported by Triesman and colleagues using this task.
These demonstrations show that visual search requires selective attention to scan items and locate targets among distractors. When targets share features with distractors, search becomes slower and requires focused attention; when targets have unique features, they “pop out” and are found quickly.
Treisman reported the feature-present/feature-absent effect, where finding a target with a distinctive feature is faster than confirming its absence. She also found the set-size effect, where reaction time increases as the number of distractors increases, especially in conjunction searches requiring focused attention.
What are saccadic eye movements? Define “fixation” and “perceptual span.” What factors affect eye movement during reading?
Saccadic eye movements are rapid jumps the eyes make between points of interest. A fixation is a brief pause between saccades when visual information is processed. Perceptual span is the region of effective vision during a fixation, extending several letters around the fixation point.
Eye movements during reading are affected by word frequency, word length, syntactic complexity, and reader skill. Familiar, predictable text produces fewer and shorter fixations, whereas complex or unfamiliar material causes longer and more frequent fixations.
Describe the two attentional networks that have been identified by neuroscience researchers, and explain the role they play in attentional phenomenon.
Neuroscience identifies the alerting network and the orienting network. The alerting network maintains a state of readiness to process incoming stimuli and is associated with frontal and parietal regions of the right hemisphere.
The orienting network directs attention to specific spatial locations or sensory inputs and involves the parietal cortex, superior colliculus, and thalamus. Together, these networks regulate preparedness and the shifting of attention in response to environmental demands.
Summarize Treisman’s feature-integration theory of attention. How does Treisman’s feature-integration explain feature-present/feature-absent effects and illusory conjunctions? Be sure to include a description of the binding problem and current status of the theory.
Feature-integration theory proposes that individual features such as colour, shape, and orientation are processed automatically in parallel, but focused attention is required to bind them into unified objects. The binding problem refers to how the brain correctly combines features processed in different regions into a coherent perception.
The theory explains feature-present effects because single features are detected automatically, while feature-absent searches require item-by-item attention. Illusory conjunctions occur when attention is overloaded and features are incorrectly combined. Current research supports feature binding but suggests binding may sometimes occur without focused attention, indicating revisions to the original theory.
Define “consciousness” as used in the Matlin and Farmer text. Distinguish between consciousness and attention.
Comment: Many examples can be given where consciousness and attention are disassociated. An alarming experience of this disassociation can happen when we are driving. Sometimes we can travel several blocks, then suddenly realize that we were not paying attention! This experience shows how consciousness and attention are not identical. Can you think of other examples?
Consciousness is awareness of external stimuli or internal mental events. Attention is the process of concentrating mental resources on specific information. Consciousness involves subjective experience, whereas attention determines what information receives priority processing.
Comment: Many examples can be given where consciousness and attention are disassociated. An alarming experience of this disassociation can happen when we are driving. Sometimes we can travel several blocks, then suddenly realize that we were not paying attention! This experience shows how consciousness and attention are not identical. Can you think of other examples?
Summarize the research findings of each of the following. What do they reveal about consciousness?
consciousness about processing (Do Demonstration 3.3)
thought suppression (Do Demonstration 3.4)
blindsight
Research on consciousness about processing shows people are often unaware of the mental processes guiding perception and decisions, yet these processes still influence behavior. Thought suppression research shows attempts to avoid certain thoughts often make them more persistent, revealing limits of conscious control.
Blindsight occurs when individuals with visual cortex damage respond to visual stimuli without conscious awareness. These findings show consciousness is not necessary for perception or action, and much cognitive processing occurs outside conscious awareness.
