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Letter to the Editor

Lives without imagery e Congenital aphantasia

Adam Zeman a,*, Michaela Dewar b and Sergio Della Sala c

a University of Exeter Medical School, College House, St Luke's Campus, Exeter, UK b Department of Psychology, School of Life Sciences, Heriot-Watt University, Edinburgh, UK c Human Cognitive Neuroscience, University of Edinburgh, Edinburgh, UK

a r t i c l e i n f o

Article history:

Received 3 March 2015

Reviewed 5 May 2015

Revised 18 May 2015

Accepted 20 May 2015

Published online 3 June 2015

* Corresponding author. University of Exeter E-mail addresses: [email protected]

http://dx.doi.org/10.1016/j.cortex.2015.05.019 0010-9452/© 2015 Elsevier Ltd. All rights rese

agnosia and imagery loss, and ii) ‘imagery generation’ deficits

selectively disabling imagery (Farah, 1984).

count of ‘blind imagination’, with the important difference

1. Introduction

Visual imagery is, for most of us, a conspicuous ingredient of

everyday experience, playing a prominent role in memory,

daydreaming and creativity. Galton, who pioneered the

quantitative study of visual imagery with his famous ‘break-

fast-table survey’, reported a wide variation in its subjective

vividness (Galton, 1880). Indeed, some participants described

‘no power of visualising’. This phenomenon has received little

attention since, though Faw reported that 2.1e2.7% of 2,500

participants ‘claim no visual imagination’ (Faw, 2009).

The experience of voluntary imagery is associated with

activity in fronto-parietal ‘executive’ systems and in posterior

brain regions which together enable us to generate images on

the basis of our stored knowledge of appearances

(Bartolomeo, 2008). The relative contributions of lower and

higher order visual regions to the experience of visual imagery

are debated (Bartolomeo, 2008). Clinical reports suggest the

existence of two major types of neurogenic visual imagery

impairment: i) visual memory disorders, causing both visual

Medical School, College (A. Zeman), m.dewar@hw

rved.

In 2010 we reported a particularly ‘pure’ case of imagery

generation disorder, in a 65 year old man who became unable

to summon images to the mind's eye after coronary angio- plasty (Zeman et al., 2010). Following a popular description of

our paper (Zimmer, 2010), we were contacted by over twenty

individuals who recognised themselves in the article's ac-

that their imagery impairment had been lifelong. Here we

describe the features of their condition, elicited by a ques-

tionnaire, and suggest a name e aphantasia e for this poorly

recognised phenomenon.

2. Results

21 individuals contacted us because of their lifelong reduction

of visual imagery. We explored the features of their condition

with a questionnaire devised for the purpose and the Vivid-

ness of Visual Imagery Questionnaire (VVIQ) (Marks, 1973) (see

Supplementary Material for further details). Participants

typically became aware of their condition in their teens or

twentieswhen, through conversation or reading, they realised

that most people who ‘saw things in the mind's eye’, unlike our participants, enjoyed a quasi-visual experience. 19/21

were male. 5/21 reported affected relatives. 10/21 told us that

all modalities of imagery were affected. Our participants rat-

ing of imagery vividness was significantly lower than that of

121 controls (p < .001, Mann Whitney U test e see Fig. 1). Despite their substantial (9/21) or complete (12/21) deficit in

voluntary visual imagery, as judged by the VVIQ, the majority

of participants described involuntary imagery. This could

occur during wakefulness, usually in the form of ‘flashes’ (10/

House, St Luke's Campus, Exeter EX1 2LU, UK. .ac.uk (M. Dewar), [email protected] (S. Della Sala).

Fig. 1 e Distribution of Vividness of Visual Imagery

Questionnaire (VVIQ) scores in participants with

aphantasia and control participants (VVIQ range extends

from 16, lowest imagery score to 80, highest imagery

score).

c o r t e x 7 3 ( 2 0 1 5 ) 3 7 8e3 8 0 379

21) and/or during dreams (17/21). Within a group of partici-

pants who reported no imagery while completing the VVIQ,

10/11 reported involuntary imagery during wakefulness and/

or dreams, confirming a significant dissociation between

voluntary and involuntary imagery (p < .01, McNemar Test). Participants described a varied butmodest effect onmood and

relationships. 14/21 participants reported difficulties with

autobiographical memory. The same number identified

compensatory strengths in verbal, mathematical and logical

domains. Their successful performance in a task that would

normally elicit imagerye ‘count howmanywindows there are

in your house or apartment’ e was achieved by drawing on

what participants described as ‘knowledge’, ‘memory’ and

‘subvisual’ models.

3. Discussion

4antası́a, phantasia, is the classical Greek term for imagina-

tion, defined by Aristotle as the ‘faculty/power by which a

phantasma [image or mental representation] is presented to

us’ (Aristotle, translated Hamlyn, 1968). We propose the use of

the term ‘aphantasia’ to refer to a condition of reduced or

absent voluntary imagery. Terms used previously in related

contexts include ‘defective revisualisation’ (Botez, Olivier,

Vezina, Botez, & Kaufman, 1985) and ‘visual irreminiscence’

(Nielsen, 1946).

Sceptics could claim that aphantasia is itself a mere fan-

tasy: describing our inner lives is difficult and undoubtedly

liable to error (Hurlburt & Schwitzgebel, 2007). We suspect,

however, that aphantasia will prove to be a variant of neuro-

psychological functioning akin to synaesthesia (Barnett &

Newell, 2008) and to congenital prosopagnosia (Gruter,

Gruter, Bell, & Carbon, 2009). Indeed, aphantasia may have

some specific relationship to these disorders, as congenital

prosopagnosia is associated with unusually low (Gruter et al.,

2009), and synaesthesia with unusually high (Barnett &

Newell, 2008), VVIQ scores.

The participants described here were self-selected and

some of our findings, such as the male predominance, may

reflect the readership of a science magazine like Discover.

There is a need, therefore, for further study in a more repre-

sentative sample. The existence of lifelong ‘aphantasia’ raises

numerous additional questions. How commonly does

congenital aphantasia occur? Existing data suggest a fre-

quency of around 2% but there is no fully reported large scale

study. The evidence of familial occurrence should be investi-

gated further. Does congenital aphantasia have objective

neuropsychological associations? Correlations between im-

agery vividness and cognitive functioning have been elusive in

the past, but recently developedmeasures of autobiographical

memory (Levine, Svoboda, Hay,Winocur,&Moscovitch, 2002),

imaginative thinking and ‘visual-object intelligence’

(Blazhenkova & Kozhevnikov, 2010) open up new avenues for

exploration. Personality and mood may also be relevant vari-

ables. Are there subtypes of congenital aphantasia? The de-

scriptions given by our participants suggest that in some cases

visual memory is preserved even if visual imagery is absent,

while others may rely entirely on non-visual representations

in memory tasks; the relationship between aphantasia and

congenital prosopagnosia also deserves further study. If, as

we hypothesise, the absence or reduction of visual imagery

has neural correlates, can we discover these? We are opti-

mistic that modern structural and functional brain imaging

may help to answer questions about the nature of visual im-

agery that were first posed in ancient Greece and first quan-

tified at Sir Francis Galton's breakfast table over a hundred years ago.

Supplementary data

Supplementary data related to this article can be found at

http://dx.doi.org/10.1016/j.cortex.2015.05.019.

r e f e r e n c e s

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