Freud was right: Inhibitory
processes in memory
Chris Moulin
c.j.a.moulin@leeds.ac.uk
Aims & Objectives
• Aim: to describe current studies in
inhibition
• By the end of this lecture and associated
reading you should be able to:
Define what inhibition is
Describe inhibitory processes for a number of key
cognitive systems
Describe inhibition in terms of neuroimaging, patient
studies, connectionism, and expeimentation
Some Reading
Hasher, L., & Zacks, R. T. (1988). Working memory, comprehension, and aging: A review and a new view. In G. H. Bower
(Ed.), The psychology of learning and motivation (Vol. 22, pp. 193-225). San Diego, CA: Academic Press
Shilling VM, Chetwynd A, Rabbitt PMA (2002). Individual inconsistency across measures of inhibition: an investigation of
the construct validity of inhibition in older adults. Neuropsychologia, 40: 605-619 8
Wegner, D.M. (1994). Ironic Processes of Mental Control. Psychological Review, 101: 34-52
Burgess, P.W., Shallice, T. (1996). Response suppression, initiation and strategy use following frontal lobe lesions.
Neuropsychologia 34: 263-272
Michael C. Anderson, Kevin N. Ochsner, Brice Kuhl, Jeffrey Cooper, Elaine Robertson, Susan W. Gabrieli, Gary H. Glover,
John D. E. Gabrieli (2002). Neural Systems Underlying the Suppression of Unwanted Memories Science, 303: 232 235.
Perfect, T. J., Moulin, C. J. A., Conway, M. A., & Perry, E. (2002). Assessing the inhibitory account of retrieval-induced
forgetting with implicit-memory tests. Journal of Experimental Psychology: Learning Memory and Cognition, 28, 11111119.
Moulin, C.J.A. Perfect, T.J., Conway, M.A., North, A.S., Jones, R.W., & James, N. (2002). Retrieval Induced Forgetting in
Alzheimer’s disease. Neuropsychologia, 40: 862-867.
Anderson, M. C. & Bjork, R. A. (1994). Mechanisms of inhibition in long-term memory: a new taxonomy. In D. Dagenbach
& T. H. Carr (Eds.) Inhibitory processes in attention, memory and language (pp. 265-325). San Diego: Academic
Press.
Anderson, M. C., Bjork, R. A, & Bjork. E. L. (1994). Remembering can cause forgetting: Retrieval dynamics in long-term
memory. Journal of Experimental Psychology: Learning, Memory and Cognition, 20, 1063-1087.
Anderson, M. C. & Spellman, B. A. (1995). On the status of inhibitory mechanisms in cognitition: memory retrieval as a
model case. Psychological Review, 102, 68-100.
“Freud was right”
• "Sometimes, a cigar is just a cigar.”—
Freud
Freud’s view
• Inhibition as "the expression of a
restriction of an ego-function. A
restriction of this kind can itself have
very different causes.” Symptoms and
Anxiety (1925).
Repression
• Freud is credited with the idea that
Memories can be willfully or
unintentionally
suppressed/forgotten/inhibited
• This is a protective, healthy
mechanism
• Modern view: Repressed memories
are contentious – e.g. childhood
Plan
• What might inhibition be & why is it necessary?
• Thought control
• Inhibition of:
Attention
Working memory
Long term memory
• Inhibition in context: Cognitive aging
What is inhibition?
• Inhibition is the suppression of
otherwise active concepts or
processes.
• Over to you: Why’s it necessary?
What is inhibition for?
To prevent unwanted information
being activated
• To stop unwanted information
entering working memory
• Perceptual/Attentional selection
• To suppress prepotent responses
• A mechanism of forgetting
Why inhibition?
“… if we remembered everything, we should
on most occasions be as ill off as if we
remembered nothing.”
James, 1890
• Retrieval inhibition: the successful
inhibition of competitor information – a
normal healthy process
• Car Parking
Eternal Sunshine
Varieties of inhibition
• Clinical tests of inhibitory function
work at many levels…
Thought control
• Like the white bear
task. Wegner (1994).
•
•
•
•
•
Sleep
Alcohol
Happiness
Erectile function
PTSD
History: Inhibition
• Cognitive models of inhibition were driven by
the fact that neurones can be inhibitory or
excitatory
• Inhibition is a frontal function (from lesion
studies). Inhibition first considered from a
neuropsych. perspective.
• Famous case: Phineas Gage
Contemporary view
The ability to suppress prepotent responses
(Burgess & Shallice, 1996): The whole town
came to hear the mayor fart.
The Supervisory attentional system (Shallice)
Imaging work: Nielson, Langenecker, Garavan
(2002). Right prefrontal area (and older
adults are more bilateral)
Retrieval induced forgetting
“A striking implication of current
memory theory is that the very act of
remembering may cause forgetting.”
Anderson, Bjork & Bjork, 1994.
• Retrieval induced forgetting paradigm
RIF
• Retrieval Induced Forgetting
Anderson, Bjork & Bjork, 1994
• Ideal test of automatic inhibition
• Inhibition is an automatic product of retrieving a
competing item in memory
• E.g.
reading about De Clerambault’s Syndrome
couldn’t recall Capgras Syndrome
RIF Paradigm
Study
Fruit – Apple
Fruit – Orange
Tool – Hammer
Tool – Saw
Metal – Silver
Metal - Gold
Practice
Fruit – A___
Tool – H___
x3
Cued Recall
Fruit – Apple
Fruit – Orange
Tool – Hammer
Tool – Saw
Metal – Silver
Metal - Gold
Type
RP+
RPRP+
RPU
U
Cued Recall
• Three kinds of items
RP+ : practiced items from practice
stage
RP- : unpracticed items from
categories that were practiced.
U : unpracticed items from
unpracticed categories
Anderson, Bjork & Bjork, 1994
100
80
60
Recall
40
20
0
RP+
RP-
U
Anderson & Spellman’s explanation of
RIF
• Pattern suppression / feature
competition.
Pattern suppression model
Blood Tomato Straw Crackers
berry
+8
-2
-2
0
The critical nature of cue independence
• “… using an independent retrieval cue during
the test phase … allowed us to establish that
variations in the amount of retrieval induced
forgetting … reflected feature level
changes to the affected items
themselves.” (Anderson, Green and
McCulloch, 2000, p.1154).
Inhibition in Context
Cognitive Aging
Hasher & Zacks, 1988
Hasher & Zacks say that cognitive
decline in older adults could all be
due to an inability to suppress
irrelevant information from working
memory
How come?
Working memory as ‘General Capacity’.
General Capacity
“(1) Cognitive functioning is constrained by
resources that are momentarily available
and (2) the multiple components assumed
to occur in almost every task vary in the
resources that each needs for maximal
performance…”
And research suggests that there may be a
general capacity decline in older adults they just don’t have mental resources to do
things
Not being able to inhibit is a drain on
resources
Garden Path Sentences
• Memory and Inhibition, e.g. Hartman
& Hasher 1991
He posted the letter without a cheque
_________
viewing
She attended a private _________
‘cheque’ & ‘viewing’ are targets, ‘stamp and school’ are generated
Garden Path II
• An implicit memory task used to
measure activation of targets and
generated words.
An implicit task:
school
The boy was
disappointed he did not get
into her ________
cheque
When his meal was
finished he asked the
Garden Path III
• Older adults show increased activation
(priming) of both targets and generated
words.
• Younger adults do not show priming of
stamp and school.
• Not confounded by memory problems:
implicit memory task
Older adults summary
• Older adults show a variety of
inhibitory deficits.
• But they’re testing the model:
Some things are good, some are bad.
Can there be any one inhibition
module?
Some questions for discussion
• A global inhibitor?
• A variety of inhibitory modules?
• When’s it interference, and when’s it
inhibition?
Summary
• You should be able to:
Define inhibition
Describe a number of tasks and experiments
that demonstrate inhibitory effects
Explain how studies of inhibiton have
illuminated the study of aging
Give a complete overview of the RIF paradigm,
and a critique of its shortcomings