2. PERCEPTION
According to S. P. Robbins,
Perception can be defined as “the process by which individuals organize and interpret their
sensory impressions in order to give meaning to their environments.”
4. Gestalt Approach to Perception
Max Withheimer, Kurt Koffka and Wolfgang Kohler (Early in 20th Century)
“The whole is greater than the sum of its parts”
15. Direct Perception
Constructivist Vs Direct Perception
People are active selectors,
integrators and constructors of
information
Light hitting the retina contains
highly organized information
that requires little or no
interpretation
Gibson - People < -- > environment
Affordance → “acts or behaviours permitted by b, places or events.
16. Disruptions in Perception
Visual Agnosias- Impairment in abilities to interpret visual info.
● Apperceptive agnosia (associated with one hemisphere)
● Associative agnosia (bilateral damage)
● Prosopagnosia - (right hemisphere + some left hemisphere)
Unilateral Neglect
17. ATTENTION
Morgan & Gilliland (1942): Attention is being keenly alive to some specific factor in our
environment.
Ross (1951): Attention is the process of getting an object or thought clearly before the
mind.
In more general terms, attention can be defined as an ability to focus and maintain
interest in a given task or idea, including managing distractions.
18. Selective Attention
“Attention is focusing of consciousness on a particular object. It implies withdrawal from
some things in order to deal effectively with others. It is the taking possession of one,
out of several simultaneously possible objects or trains of thought by the mind, in clear
and vivid form.”
- William James
19. “Dichotic listening task”
Two different messages recorded so as to be heard simultaneously in opposite ears.
“Shadow”
Repeat the messages heard in one ear.
“Biaural presentation”
Tapes recorded so that both messages are heard in both ears
20. Cherry (1953)
Dichotic listening → Shadow → questioned on material from unattented message.
Reported:
● Whether the message contained speech or noise.
● Man or woman
● Could not recall the content of the message or language,
21. Broadbent (1958) - Filter Theory
Protects from “information overload” by
shutting out messages.
Exception:
Two messages contain little information /
presented slowly can be processed
simultaneously.
22. Moray (1959)
“Cocktail Party Effect”
Perspective: “important” material xn penetrate through the filter set up to block unattended messages
But, How does the filter know which message is important?
Pashler (1998) → Participants do not always hear their names. Only 33% of the participants noticed.
23. Treisman (1960) - Attenuation Theory
Experiment: Messages switched between ears.
Most participants had no idea.
Analysis:
1. Physical properties - pitch and loudness
2. Linguistic - syllables and words
3. Semantic - meaning
24. Wood and Cowan (1995)
Speech in unattented channel reversed (backwards) for 30 secs
Errors increased in percentage during 30 sec backward speech. (when they reported to have
noticed the reversal)
Conway , Cowan & Bunting (2001) → Lower working memory span
Normal message after the
backward speech
2.5 minutes
1.5 minutes
Control group
27. Spotlight Approaches
Spotlight Metaphor
● Attention directed and redirected
● Illuminates center
● Fuzzy boundaries
● Highlight more than one objects → size
Daniel Kahneman (1973) - categorizing and recognizing stimuli
Investor money metaphor → Cognitive resources, arousal and task difficulty
“Allocation policies”
Norman & Bobrow (1975) - mental effort + data
Detect a dim light in bright room / soft sound in noisy room
28. Schema Theory
Ulrich Neisser (1976)
The unattended message is simply left out or ignored
Experiment: Selective looking task
29. Inattentional Blindness
Phenomenon of not perceiving a stimulus or
change in stimulus unless you pay attention
to it.
Neisser and Becklen (1975)
Black team Vs White team (easy / hard)
46% failed to notice either umbrella /gorilla
Simon & Levin (1998) study
33. Automatic Vs Controlled Processing
Posner & Snyder (1975)
Three criteria to name a cognitive processing as automatic
● Must occur without intention
● Must occur without involving conscious awareness
● Must not interfere other mental activities.
Example: Driving home
39. Divided Attention
Attention to two or more channels of information at the same time, so that two or more
tasks may be performed concurrently. It may involve the use of just one sense (e.g., hearing)
or two or more senses (e.g., hearing and vision).
40. Dual task performance:
Spelke, Hirst & Neisser (1976)
17 weeks, 5 days a week - Reading short stories and write words dictated while reading
In 6 weeks - the scores became comparable (comprehension with/without dictation)
Explanations:
1. Alternation hypothesis (Alternate attention b/w the tasks)
2. Automaticity
3. Learn to perform two tasks together.
41. Attention Hypothesis of Automatization:
Logan & Etherton (1996)
“Attention is needed during the practice phase of a task and determines what gets learned
during the practice. Attention also determines what will be remembered”
“Learning is a side effect of attending: People will learn about things they attend to and they
will not learn about things they do not attend to”
Experiment:
2 words, spot the word that means metal
2 words, spot the green word that means metal
42. Divided Attention outside the laboratory: Cell Phones Usage
While Driving
Dual task performance in real life
Strayer and Johnston (2001)
Joystick to move cursor positioned over a moving target, press buttons according to red & green
Treatment conditions: Listening to radio & Talking over phone
Why not such distractions happen with passenger in the car?
What’s with texting while driving?
43. Summary of Divided Attention:
→ There are serious limitations on the number of things we can successfully do at once.
→ It may seem like we are doing the task simultaneously but in many cases we rapidly
switch our attentions back and forth b/w the two tasks.
→ When the tasks become more demanding it gets harder to do them simultaneously.
44. Consciousness
Consciousness is the awareness of environmental and cognitive events such as the sights
and sounds of the world as well as of one’s memories, thoughts, feelings, and bodily
sensations.
Framework for Consciousness: AWAREness (Solso, 2003; MacLin, MacLin, & Solso,
2007)
Functions of Consciousness
45. Framework for Consciousness: AWAREness
(Solso, 2003; MacLin, MacLin, & Solso, 2007)
Attention: the focusing of cognizance on external or internal things (Spotlight)
Our attention to objects is not arbitrary, but is driven by a “searching eye” looking for details
that, combined and integrated into our larger world knowledge, form the basis of a more
comprehensive consciousness.
Wakefulness: the continuum from sleep to alertness. (Arousal component)
Architecture: the physical location of the physiological structures (and their related
processes) that underpin consciousness.
46. Recall of Knowledge: the accessing of personal and world information.
● Self-knowledge is a sense of one’s own personal information.
● World knowledge, allows us to recall the many facts of our long-term memory.
● Activation of knowledge - one is conscious of another’s actions
Emotive: the affective components associated with consciousness
Novelty: the propensity not only to focus on central thoughts and events, but to seek out novel,
creative, and innovative items.
Emergence: consciousness is distinctive from other neural processes in the respect that it deals with
private and internal thoughts.
Selectivity and Subjectivity
47. Functions of Consciousness
(Pierson & Trout, 2005) argue that the only reason to have consciousness is to make
volitional movement possible. Volitional movements are those that are made by choice, not
by instinct or reflex.
Damasio (1999) has a similar view in that consciousness serves to allow us to plan our
behaviors instead of relying purely on instincts. By doing so (and coupled with self
awareness) gives us greater survivability in the environment.
Baars and McGovern (1996) suggest several functions of consciousness
