Freud was right: Inhibitory processes in

memory

Chris Moulinc.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 isDescribe inhibitory processes for a number of

key cognitive systemsDescribe inhibition in terms of neuroimaging,

patient studies, connectionism, and expeimentation

Some ReadingHasher, 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 PressShilling 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 8Wegner, D.M. (1994). Ironic Processes of Mental Control. Psychological Review, 101: 34-52Burgess, P.W., Shallice, T. (1996). Response suppression, initiation and strategy use following frontal lobe lesions. Neuropsychologia 34: 263-272Michael 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, 1111-1119.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 abuse

Plan

• What might inhibition be & why is it necessary?

• Thought control• Inhibition of:

AttentionWorking memoryLong 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 ForgettingAnderson, 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’sDe Clerambault’s Syndromecouldn’t recall CapgrasCapgras Syndrome

RIF Paradigm

StudyFruit – AppleFruit – OrangeTool – HammerTool – SawMetal – SilverMetal - Gold

PracticeFruit – A___

Tool – H___

x3x3

Cued RecallFruit – AppleFruit – OrangeTool –

HammerTool – SawMetal – SilverMetal - Gold

TypeRP+RP-RP+RP-UU

Cued Recall

•Three kinds of itemsRP+ : practiced items from practice stage

RP- : unpracticed items from categories that were practiced.

U : unpracticed items from unpracticed categories

Anderson, Bjork & Bjork, 1994

0

20

40

60

80

100

RP+ RP- U

Recall

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 _________

She attended a private _________

cheque

viewing

‘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: The boy was disappointed he did not get into her ________

When his meal was finished he asked the waiter for his _________

school

cheque

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 inhibitionDescribe a number of tasks and experiments

that demonstrate inhibitory effectsExplain how studies of inhibiton have

illuminated the study of agingGive a complete overview of the RIF

paradigm, and a critique of its shortcomings