The Psychology Book (60 page)

190 ENDEL TULVING

memorable event—such as the 9/11

terrorist attacks—occurs, are an

extreme example of this.

Tulving described recollection

from episodic memory as “mental

time travel,” involving us in a

Remembering is

revisiting of the past to access

mental time travel.

the memory. In his later work he

Endel Tulving

pointed out that episodic memory

is unique in featuring a subjective

sense of time. Specific to humans,

it involves not merely awareness of

what has been, but also of what

may come about. This unique

ability allows us to reflect on our

lives, worry about future events,

Emotional events such as weddings

and make plans. It is what enables

give rise to episodic memories. These

are stored in such a way that the

humankind to “take full advantage

person remembering relives the event,

of its awareness of its continued

in a form of “time travel.”

existence in time” and has allowed

us to transform the natural world

semantic memories are organized

provide a retrieval cue for the

into one of numerous civilizations

into meaningful categories of subject

semantic memory “Beijing,” the

and cultures. Through this facility,

matter, episodic memories are

mention of “40th birthday” might

“time’s arrow is bent into a loop.”

organized by relation to the specific

act as a cue for the retrieval of

time or circumstances in which

what had been said over that

Encoding information

they were originally stored. For

dinner. The more strongly these

Tulving realized that organization

example, a particular conversation

autobiographical memories are

is the key to efficient recall for both

may have taken place during a

associated with the time and

semantic and episodic memory, and

birthday dinner, and the memory

circumstances of their occurrence,

that the brain somehow organizes

of what was said would be stored

the greater their accessibility is

information so that specific facts

in association with that occasion.

likely to be. “Flashbulb memories,”

and events are “pigeonholed” with

Just as the category of “city” might

which are stored when a highly

related items. Recalling that specific

Endel Tulving

Born the son of a judge in Tartu,

University of Toronto, where

Estonia, Endel Tulving was

he graduated in psychology in

educated at a private school for

1953, and took his MA degree in

boys, and although a model

1954. He then moved to Harvard

student, he was more interested

where he gained a PhD for his

in sports than academic subjects.

thesis on visual perception.

When Russia invaded in 1944,

In 1956, Tulving returned to the

he and his brother escaped to

University of Toronto, where he

Germany to finish their studies

continues to teach to this day.

and did not see their parents again

until the death of Stalin 25 years

Key works

later. After World War II, Tulving

worked as a translator for the

1972
Organization of Memory

American army and briefly

1983
Elements of Episodic

attended medical school before

Memory

emigrating to Canada in 1949. He

1999
Memory, Consciousness,

was accepted as a student at the

and the Brain

COGNITIVE PSYCHOLOGY 191

information is then made easier

Different types of memory
are

by direction to the appropriate

physically distinct, according to

pigeonhole—the brain “knows

Tulving, because each behaves and

Semantic memory

functions in a significantly

where to look” for the memory it

stores facts and

different way.

knowledge.

wants and can narrow down the

search. The implication, he

believed, is that the brain encodes

each memory for storage in long-term

memory, so that specific memories

Episodic memory

can be located for recollection by a

stores events and

more general retrieval cue. The

recollections.

cues that prompt episodic memory

are usually sensory. A specific sound,

such as a piece of music, or a scent

can trigger a complete memory.

Tulvings’s theory of the

Procedural memory

“encoding specificity principle”

stores methods and

was especially applicable to

techniques.

episodic memory. Memories of

specific past events are encoded

according to the time of their

occurrence, along with other

recollection, even though the

are active during encoding and

memories of the same time. He

information is stored and available

retrieval of memory, and establish

found that the most effective cue

in long-term memory.

that episodic memory is associated

for retrieving any specific episodic

Unlike previous theories of

with the medial temporal lobe and,

memory is the one which overlaps

memory, Tulving’s encoding principle

specifically, the hippocampus.

with it most, since this is stored

made a distinction between memory

Partly due to his unorthodox

together with the memory to be

that is available and that which is

and untutored approach, Tulving

retrieved. Retrieval cues are

accessible. When someone is unable

made innovative insights that

necessary to access episodic

to recall a piece of information, it

proved inspirational to other

memory, but not always sufficient,

does not mean that it is “forgotten”

psychologists, including some of

because sometimes the relationship

in the sense that it has faded or

his former students such as Daniel

is not close enough to allow

simply disappeared from long-term

Schacter. Tulving’s focus on storage

memory; it may still be stored, and

and retrieval provided a new way of

therefore be available—the problem

thinking about memory, but it was

is one of retrieval.

perhaps his distinction between

semantic and episodic memory that

Scanning for memory

was his breakthrough contribution.

Tulving’s research into the storage

It allowed subsequent psychologists

Relating what we know

and retrieval of memory opened up

to increase the complexity of the

about the behavior of memory

a whole new area for psychological

model to include such concepts as

to the underlying neural

study. The publication of his

procedural memory (remembering

structures is not

findings in the 1970s coincided

how to do something), and the

at all obvious. That’s

with a new determination by many

difference between explicit memory

real science.

cognitive psychologists to find

(of which we are consciously aware)

Endel Tulving

confirmation of their theories in

and implicit memory (of which we

neuroscience, using brain-imaging

have no conscious awareness,

techniques that had just become

but which nonetheless continues

available. In conjunction with

to affect us). These topics remain

neuroscientists, Tulving was able

of great interest to cognitive

to map the areas of the brain that

psychologists today. ■

192

PERCEPTION IS

EXTERNALLY GUIDED

HALLUCINATION

ROGER N. SHEPARD (1929– )

IN CONTEXT

APPROACH

H
ow the mind makes use

of information gathered

from the external world

has been a major concern for

Perception

philosophers and psychologists

BEFORE

throughout history. Exactly how

do we use the information gained

1637
René Descartes in his

through our senses? In the early

treatise
Discourse on the

1970s, cognitive and mathematical

Method
suggests that though

psychologist Roger Shepard

our senses can be deceived,

proposed new theories of how

we are thinking beings with

An optical illusion
creates confusion

the brain processes “sense data.”

in the viewer, demonstrating that we are

innate knowledge.

Shepard argued that our brains

not just perceiving, but also attempting

1920s
Gestalt theorists study

to fit the sensory data to what we

not only process sense data, but also

visual perception, finding that

already understand in the mind’s eye.

make inferences from it, based on an

people tend to view objects

internal model of the physical world

comprising composite parts

where we can visualize objects in

world and mental visualization.

as a unified whole.

three dimensions. The experiment

Perception, Shepard said, is

he used to prove this, in which

“externally guided hallucination,”

1958
Donald Broadbent’s book

subjects tried to ascertain whether

and he described the processes

Perception and Communication

two tables—each drawn from a

of dreaming and hallucination as

introduces a truly cognitive

different angle—were the same,

“internally simulated perception.”

approach to the psychology

showed that we are able to perform

Shepard’s research introduced

of perception.

what Shepard called “mental

revolutionary techniques for

rotation:” turning one of the tables

identifying the hidden structure

AFTER

in our mind’s eye for comparison.

of mental representations and

1986
American experimental

Shepard used a series of optical

processes. His work in visual and

psychologist Michael Kubovy

(and aural) illusions to demonstrate

auditory perception, mental imagery,

publishes
The Psychology

that our brains interpret sense data

and representation has influenced

of Perspective and

using both knowledge of the external

generations of psychologists. ■

Renaissance Art
.

See also:
René Descartes 20–21 ■ Wolfgang Köhler 160–61 ■

Jerome Bruner 164–65 ■ Donald Broadbent 178–85 ■ Max Wertheimer 335