What is a percept?
A percept refers to an individual’s perception of an object, person or event. This occurs instantaneously, mostly outside of conscious awareness. We are only aware of the product, and not the process.
What is sensation?
Sensation refers to the psychological processes through which we receive incoming information.
What is perception?
Perception refers to the psychological processes through which we organize and interpret incoming information.
What is bottom-up processing?
Bottom-up processing, or data-driven processing, refers to perceptual processes where information flows from the stimulus to subsequent neural activity to stimulus identification.
What is top-down processing?
Top-down processing, or conceptually-driven processing, refers to perceptual processes where we use our expectations, knowledge and surrounding context to identify a stimulus.
What is the constructive view?
The constructive view emphasises the role of top-down processing in arriving at a percept.
What is the direct view?
The direct view emphasises the role of bottom-up processing in arriving at a percept.
What is pre-attentive processing?
Pre-attentive processing refers to processing before attention is directed at a stimulus array. During this time, individuals organise incoming stimulus array into discrete elements.
What is post-attentive processing?
Post-attentive processing refers to processing after attention is directed at a stimulus array. During this time, individuals identify these elements for further processing and categorisation.
What is grouping?
Grouping refers to an individual’s ability to organise incoming stimulus array into discrete elements. The principle of grouping applies not only to visual stimuli but to auditory stimuli as well.
What are the principles of visual organisation?
The principles of visual organisation refer to a set of principles that account for the “order” we see in our visual environment.
What is proximity?
Proximity refers to an individual’s tendency to group objects that are near one another together.
What is similarity?
Similarity refers to an individual’s tendency to group objects that are similar together.
What is good continuation?
Good continuation refers to an individual’s tendency to perceive lines as flowing naturally in a single direction.
What is closure?
Closure refers to an individual’s tendency to complete any incomplete contours.
What is common fate?
Common fate refers to an individual’s tendency to group objects that are moving in the same direction or same speed together.
What is common region?
Common region refers to an individual’s tendency to group objects that belong to a common designated area together.
What is synchrony?
Synchrony refers to an individual’s tendency to group objects that occur at the same time together.
What is element connectedness?
Element connectedness refers to an individual’s tendency to group objects that are connected to each other together.
Describe the Palmer and Beck (2007) repetition discrimination task experiment.
Participants were presented with a repetition discrimination task, where they had to indicate if the repeated elements were circles or squares.
In within-group trials, the repeated elements were part of the same perceptual group.
In the between-group trials, the repeated elements were not part of the same perceptual group.
The researchers found that RT for within-group trials was faster than RT for between-group trials.
These results indicate that participants had a tendency to group particular elements together.
What is figure-ground?
Figure-ground refers to an individual’s tendency to separate a visual scene into a background and a figure that appears to be superimposed against that background.
Relative to ground, figures are smaller, more symmetrical, meaningful, surrounded by other elements in the visual scene, lower in the visual field and display convexity (MeSSy CoLS).
What is global precedence?
Global precedence refers to an individual’s tendency to process global features first and automatically as compared to local features
Describe the Navon (1997) global precedence study.
Participants were presented with big letters made up of small objects. The stimulus were consistent (global H and local H), conflicting (global H and local S) or control (global H with local neutral symbol).
In the global-directed condition, participants were asked to identify the large object.
In the local-directed condition, participants were asked to identify the small object.
Overall, global letters participants reported global letters more quickly than local objects.
RT to identify large object was not affected by the identity of the small objects.
RT to identify small object was affected by the identity of the large object. If the large object conflicted, RT was slower.
This suggests a global precedence, where even when instructed to identify local features, participants could not help but process global features first.
Describe the Davidoff, Fonteneau and Fagot (2008) Himba study.
Himba and UK participants were asked to indicate which comparison stimulus was most like the target. The garget had a circle as a global feature, and circles as local features. The first comparison stimulus had a circle as a global feature, and squares as local features (choosing this suggests global precedence). The second comparison stimulus had a square as a global feature and circles as local features (choosing this suggests local precedence).
UK participants displayed global precedence, while Himba participants displayed local precedence.
What is strong synaesthesia?
Synaesthesia refers to a phenomenon where input to one sensory modality produces a perceptual experience in that modality and another modality as well (e.g. experience a musical chord as green).
What is grapheme-colour synaesthesia?
Grapheme-colour synaesthesia refers to a form of strong synaesthesia where numbers or letters are linked to the experience of colour.
What is the McGurk effect?
The McGurk effect refers to the phenomenon where the simultaneous presentation of an auditory stimulus (/b/) and a visual stimulus (/g/) leads to a blended perception (/d/).
Describe the Bargary, Barnett, Mitchell, and Newell (2009) strong synaesthesia experiment.
Grapheme-colour synaesthetes see one colour (e.g. purple) when they hear /b/ and see another colour (e.g. pink) when they hear /d/.
Grapheme-colour synaesthetes were presented with the McGurk effect. If synaesthesia is due to sensory processing, the participants will see purple since it is caused by the sensation of a /b/. If synaesthesia is due to perceptual processing, they will see pink since it is caused by the blended perception of a /d/.
The participants saw pink, which indicates that strong synaesthesia is a result of later (perceptual) processing.
What is weak synaesthesia?
Weak synaesthesia refers to linguistic cross-modal experiences (e.g. “cool” colours).
Describe the Martino and Marks (2001) weak synaesthesia experiment.
Participants were presented with tones that were accompanied either by a black or a white square.
Participants were asked to classify the tone as either “high” or “low”.
The results show that when the square was black, the participants classified low tones more quickly than high tones. And when the square was white, the participants classified high tones more quickly than low tones.
These results suggest that weak synaesthesia is the result of experience which leads us to associate stimuli together.
What is the ventriloquist effect?
The ventriloquist effect refers to the phenomenon where sound is perceived as coming from a visual display when the visual cue is presented simultaneously with an auditory stimulus.
Describe the Schutz and Limbscomb (2007) marimba experiment.
Participants heard a single note.
In the first experimental condition, participants were shown a video where the musician displayed a long-note gesture.
In the second experimental condition, participants were shown a video where the musician displayed a short-note gesture.
In the third experimental condition, participants were not shown a video. Participants in the no video condition judged the notes to be of the same duration.
Participants in the long-gesture condition judged the note of a longer duration as compared to participants in the short-gesture condition.
These results suggest an interaction between vision and audition.
Describe the Morrot, Duchet, and Dubourdieur (2001) wine experiment.
Participants (wine experts) were presented with white wine that was coloured red, and asked to describe the smell of the wine.
The participants described the smell of the white wine with words typically associated with the smell of red wine (e.g. cherry).
These results suggest an interaction between vision and the chemical senses.
Described the Pavani, Spence, and Driver (2000) rubber hand experiment.
Participants held (but could not see) cubes that vibrated either on top or at the bottom.
The cubes that the participants could see lit up either on top or at the bottom.
The cubes that vibrated and the cubes that lit up either matched or mismatched.
Participants saw hands holding the cubes that lit up. These hands were either aligned or misaligned with their own hands.
Participants were asked to identify the source of the vibration.
According to the results, the RT to identify the source of the vibration was slower when the light mismatched the vibration than when it matched. Moreover, the presence of the dummy hands significantly accentuated this interfering effect. In the dummy hand condition, RT to identify the source of vibration when the light mismatched the vibration was even slower when the hands were misaligned with the participants’ hands than when they were aligned.
These findings suggest a rubber hand illusion, where participants experience the dummy hands as their own.
Describe the Ehrsson et al (2008) phantom hand experiment.
Participants (upper-limb amputees) saw a rubber hand holding a cube that lit up either on top or at the bottom.
Another cube vibrated either on top or at the bottom of the participants’ stumps.
Participants reported sensing touch on the rubber hand rather than on the stump, resulting in a feeling of ownership of the phantom hand.
Describe the Hotting and Roder (2004) blind and sighted experiment.
Participants were either blind or sighted individuals. They heard 1 to 4 tones, and felt 1 to 4 vibrations to the right index finger. They were then asked to identify the number of vibrations.
According to the results, as the number of tones increased, the number of vibrations increased. This effect was greater for sighted individual than blind participants.
These results support the notion that processes involved in multisensory integration differ in congenitally blind individuals and sighted individuals. However, all of the blind participants were experienced Braille readers. This means that their tactile expertise may have given them more confidence in their tactile judgments, making them less susceptible to auditory interference. This thus presents a confound to the experiment.
What are affordances?
Affordances refer to the action possibilities that a particular object offers.
Describe the Ishal et al (2008) candy experiment.
Participants were asked to retrieve candy through an aperture. The aperture sized varied across trials. There were therefore three possible outcomes: Participants could choose not to attempt to reach the candy, attempt but get stuck, or successfully retrieve the candy.
According to the results, the motor retention function (i.e. the % of trials on which an attempt was made regardless of success) was highest at the aperture threshold, and dropped precipitously below the aperture threshold.
The results suggest that participants had good aperture perception. This means that they knew when the aperture was big enough to retrieve the candy.
Describe the Davoli and Abrams (2009) hands behind back experiment.
Participants asked to determine if a target letter was present in a display on a computer screen.
The task was either difficult (many letters) or easy (few letters).
Participants were either asked to imagine their hands on sides of computer monitor or behind their back.
The results show that RT increased as display sized increased. Moreover, the increase in RT was greater when imagining hands behind back than when imagining hands on monitor.
This suggests an enhanced visual analysis for items in closer physical proximity.
What is embodied perception?
According to the embodied perception view, perception does not involve “thinking” as much as it involves the body “reacting”. This “reaction” is influenced by a variety of non-visual factors such as bodily state, emotional state and the individual’s goals.
Describe the Proffitt et. al. (1995) hill experiment.
Participants were asked to estimate the slant of two hills before a rigorous run, and after the rigorous run. These estimates were done verbally, visually and haptically.
The effects of fatigue on participants’ verbal and visual estimates were significant. The effects of fatigue on participants’ haptic judgment were insignificant.
Proffitt suggested that individuals take note of “energetic considerations” to promote “efficient energy expenditure”. For example, the hill would appear steeper to someone who is tired, or in pain, thereby discouraging them from climbing it. This illusory perception thus allows them to conserve their energies to recover.
Describe the Linkenauger et. al. (2009) traffic cone experiment.
Participants either suffered, or did not suffer, minor but chronic pain in the back and/or lower extremities. They were asked to estimate the distance from various traffic cones.
According to the results, chronic pain sufferers judged distances to be longer than those not suffering from chronic pain.
These results support the notion of individuals taking into account “energetic considerations” to “promotes energy expenditure”.
What is the evolutionary approach to perception?
According to the evolutionary approach to perception, humans evolve in ways to maximise our chances of survival. And because a key principle in survival is that energy consumption should be greater than energy expenditure, our perceptual processes have evolved to help us to make decisions that align with this principle.
What is consciousness?
Consciousness refers to our awareness of internal and external events.
What is access consciousness?
Access consciousness refers to what the cognitive system is doing. Whenever we process information, we demonstrate access consciousness.
What is phenomenal consciousness?
Phenomenal consciousness refers to our awareness of what the cognitive system is doing.
What is monitoring consciousness?
Monitoring consciousness refers to an individual’s ability to reflect on one’s cognitive processes.
What is self-consciousness?
Self-consciousness refers to an individual’s general knowledge of self (e.g. where we are from).
Why are self-reports suspect?
This is because most cognitive processes occur outside of phenomenal consciousness.
What is signal detection theory?
According to signal detection theory, perceptual experiences are the joint product of sensitivity of a particular sensory system as well as response bias (i.e. our willingness to report the perception).
What is the illusion of conscious will?
The illusion of conscious will refers to the belief that we consciously willed an action when in reality we did not. This results from the close proximity between relevant thought and action.
What is authorship processing?
Authorship processing refers to the set of psychological processes that leads an individual to attribute an event to the entities that are thought to have caused them.
Describe the Wegner et. al. (2004) illusion of conscious control experiment.
A confederate at the back gives commands to move arms while the passive participant looks into the mirror and either hears the commands or does not hear the commands. The arms that move do not belong to the participant.
Participants are asked to rate the degree to which they feel they are consciously willing the arm movement.
The results show that participants gave a higher rating when they heard command than when they did not hear the command.
These results indicate the presence of phenomenal consciousness in the absence of access consciousness.
Describe the Metcalfe and Greene (2007) computer game experiment.
Participants played a video game in which X and O moved downward on a screen.
Participants were asked to use mouse to move cursor to touch the X but not the O. Participants received 1 point for each X they touched, and the game was stopped at random times to ask participants to rate the extent to which they had been in control of the cursor.
The experimenter manipulated the speed at which the X and O moved down the screen (fast/slow), the fidelity of the mouse-cursor relationship (no turbulence/turbulence) and how close the cursor had to be to the X to receive the point (magic/no magic).
According to the results, although the hit rates (proportion of X that were touched) were greater in slow condition than fast condition, the judgment of agency (JoA) ratings were the same. This indicates that participants were metaognitively aware that their performance was due to the speed.
Hit rates in turbulence and non turbulence conditions were almost identical, but JoA ratings were higher in no turbulence condition. This indicates that participants were metacognitively aware that their performance was due to turbulence.
Hit rates and JoA ratings were greater in the magic condition than in the no magic condition, but the difference was greater in JoA ratings. This indicates that participants were metacognitively aware that their performance was due to the “magic”.
Overall, these results indicate that participants have good metacognitive awareness of their own sense of agency.
What is blindsight?
Blindsight refers to the presence of access consciousness in the absence of phenomenal consciousness.
Describe the Weiskrantz (1986) D.B. experiment.
D.B. was completely blind in left visual field. He was unable to identify objects (no phenomenal consciousness) but had knowledge of objects (e.g. location) (access consciousness).
D.B. was presented to stimuli in the left visual field, and he reported not seeing anything.
He was given a forced-choice procedure to see what he knew about the stimuli. In this procedure, he was presented with two alternative answers, and “I don’t know” is not allowed.
The results show that his performance was well above chance, showing the presence of access consciousness.
What two distinct neurologic systems underlie vision?
The “what” system is located primarily in the visual cortex, and is responsible for identifying, recognising and becoming aware of visual stimuli. It occurs relatively late in visual processing.
The “where” system is located primarily in the subcortical structures, and are responsible for the detection and localisation of objects. It occurs relatively early in visual processing.
In blindsight, these two systems are disscociated.
What is subliminal perception?
Subliminal perception refers to the occurrence of semantic processing outside of phenomenal consciousness.
What is semantic priming?
Semantic priming refers to the tendency for the processing of one stimulus to enhance the speed at which a related stimulus is processed. This does not enhance the speed with which an unrelated target is processed.
Discuss the Costello et. al. (2009) binocular suppression experiment.
Participants saw a prime word in both eyes (e.g. salt).
In one eye, the target word was presented and increased in brightness until it became visible. The target word was either related to the prime word (e.g. pepper) or unrelated (e.g. basket).
In the other eye, a colour patch was presented. This is so that the participant consciously perceives the colour patch and not the target word.
According to the results, the initially visible target word emerged from suppression sooner when the prime word was related than when it was unrelated.
This indicates that even when the target word was completely invisible, it was undergoing semantic processing and thus could be primed by the visibly presented prime word.
What are some problems with the study of subliminal perception?
The question “Can there be subliminal influences on behaviour” can be answered in different ways depending on how one defines “subliminal” and “influence on behaviour”.
Describe the Marcel (1983) colour patch experiment.
Participants were asked to identify the colour of a patch. This patch was preceded by a prime word that was either neutral (e.g. table) or matched (e.g. blue).
The prime word was presented either at a supraliminal level (above the threshold of conscious awareness) or a subliminal level (below the threshold of conscious awareness).
According to the results, priming occurred in both conditions. However, priming was larger in the supraliminal condition as compared to the subliminal condition. The problem with this experiment is that Marcel defined “subliminal” subjectively, in terms of what the participants report they had perceived. However, according to signal detection theory, participant reports are prone to response bias.
Describe the Cheesman and Merikle (1984) second colour patch experiment.
Participants were asked to identify the colour of a patch. This patch was preceded by a prime word that was either neutral (e.g. table) or matched (e.g. blue).
The prime word was presented either at a supraliminal level (above the threshold of conscious awareness) or a subliminal level (below the threshold of conscious awareness).
The level of conscious awareness was either objective or subjective.
Objective threshold refers to the level of exposure where participants could not guess what colour had occurred with any level of proficiency.
Subjective threshold refers to the level of exposure where participants reported that they could not see the prime word, but could guess what colour had occurred at a rate higher than 50% (i.e. chance).
According to the results, primes presented below an objective threshold failed to influence performance, while primes that were presented below a subjective threshold produced a statistically significant degree of priming.
The researchers thus conclude that the reality of subliminal priming depends on how one defines this threshold of conscious awareness.
Describe the Greenwald et. al. (1991) fake tape experiment.
Participants took tests to assess their memory and self-esteem.
They were then given subliminal messages embedded in tapes. The tapes were labelled as either memory improvement or self-esteem improvement. However, the label was unrelated to the content of subliminal message.
Participants were asked to listen to the tapes each day for one month. After which, they took another test to assess memory and self-esteem. They were also asked if they felt their memory or self-esteem had improved.
According to the results, subliminal message had no effect on memory or self-esteem. However, those with tapes with the memory improvement label felt that their memory had improved, while those with the self-esteem improvement label felt that their self-esteem had improved.
Describe the Vokey and Reed (1988) Psalm and Jaberwocky experiment.
Experimenter listened to a psalm and Jaberwocky played backwards and found 6 “meaningful” passages.
Participants were given these recordings.
In one experimental condition, they were asked to identify for the passages that the experimenter had heard.
In the other experimental condition, they were asked to identify any meaningful passages.
According to the results, participants were only able to identify the passages if they were told in advance.
This suggests that top-down processing is at work. Although the data is meaningless, participants’ expectations and knowledge impose order on the data.
What is the general consensus on subliminal perception?
Most researchers are sceptical of the effectiveness of subliminal perception.