Memory

Question 1

Olton & Sameulson (1976)

Answer 1

Radial arm maze

Question 2

Beatty & Shavalia (1980)

Answer 2

8 arm RAM - all arms had food at start of trial. Allowed rats to visit four arms, and then removed them from the maze.
With increasing RI found decreasing % correct RA visits.

Question 3

Harper (2004)

Answer 3

Red and blue - different drugs.
Red = mainly increased reference/long term memory errors = visits to arm that never had food. MDMA/ecstasy
Blue = mainly increased working/short term memory errors = visits to arms they already visited. Ach receptor blocker

Question 4

White & Wixted (1999)

Answer 4

Log d vs RI

• Better performance with longer ITI
• Decrease accuracy with increasing RI

Question 5

TDH - temporal discrimination hypothesis

Answer 5

Discriminating between two different times, between last seeing the two comparisons.
Matching accuracy will be a function of both the time since the sample was presented, and the time since the incorrect comparison appeared as a sample.

Question 6

Worsham (1975)

Answer 6

DMTS task should be hard if the incorrect stimulus had been the sample on the previous trial, but easy if the incorrect stimulus had not been the sample for many trials.
Showed this: decreased accuracy with harder sequences vs easy sequences in monkeys.

Question 7

Worsham (1975) EXP 2

Answer 7

According to TDH, you should get more accurate if the task is more complicated = more samples mean the incorrect sample has been seen less often. This is because the probability of the incorrect choice being the last sample decreases with increasing number of possible samples.
Showed this: increasing sample set size –> increased % correct.

Question 8

Grant & Roberts (1973)

Answer 8

Experimental trial: incorrect, interfering stimulus presented immediately before the sample.
Control trial: just the sample was presented
–> Found that the subjects had far less accuracy with the interfering stimulus – consistent with TDH, because there is little time difference between the correct and incorrect stimuli.

Question 9

Trace decay theory (TDT)

Answer 9

At choice phase, subject compares each of the choice stimuli to a memory trace of the sample - responds to whichever was more similar. Memory trace decays over time – forgetting function.
But the memory trace is also effected by factors such as vividness, length of presentation (which TDH does not account for).
Also accounts for retroactive interference.

Question 10

Grant (1976) - TDT

Answer 10

Varied sample duration from 1-14s
Found more accurate memory with longer sample duration. (but surely TDH does predict this anyway).
Rate of decay independent of strength of initial stimulus..

Question 11

Roberts & Grant (1978)

Answer 11

Retroactive interference. Presenting stimuli during the RI impairs performance. Not consistent with TDH but is with TDT.
House light on = interference = faster rate of forgetting.

Question 12

Two models of memory decay

Answer 12

1) Hyperbolic decay
2) Exponential decay
-both use log d
Exponential generally better –> implies forgetting happens at a constant rate. Says that rate of forgetting is independent of initial discriminability – so logd and logb should be independent.

Question 13

Things that effect log do not log b

Answer 13

1) Sample duration (Grant)
2) Sample disparity (White)
3) Number of responses required to sample (White)

Question 14

Things that effect log b and not logdo

Answer 14

1) Retroactive interference = events during the ICI
2) Differential outcomes effect
- arranging different reinforcers for the two correct responses decreases rate of forgetting = more association