Loss of imagery phenomenology with intact visuo-spatial task performance: A case of ‘blind imagination’

Abstract

The capacity for imagery, enabling us to visualise absent items and events, is a ubiquitous feature of our experience. This paper describes the case of a patient, MX, who abruptly lost the ability to generate visual images. He rated himself as experiencing almost no imagery on standard questionnaires, yet performed normally on standard tests of perception, visual imagery and visual memory. These unexpected findings were explored using functional MRI scanning (fMRI). Activation patterns while viewing famous faces were not significantly different between MX and controls, including expected activity in the fusiform gyrus. However, during attempted imagery, activation in MX's brain was significantly reduced in a network of posterior regions while activity in frontal regions was increased compared to controls. These findings are interpreted as suggesting that MX adopted a different cognitive strategy from controls when performing the imagery task. Evidence from experimental tasks thought to rely on mental imagery, such as the Brooks' matrices and mental rotation, support this interpretation. Taken together, these results indicate that successful performance in visual imagery and visual memory tasks can be dissociated from the phenomenal experience of visual imagery.

Dynamic visual noise reduces confidence in short-term memory for visual information

“…However, although parsimonious, this conceptualisation does not fit with current models where visual imagery and visual STM are subserved by separate cognitive systems (Logie, 1995(Logie, , 2003(Logie, , 2011Pearson, 2001;Quinn & McConnell, 2006). Indeed, recent data from both laboratory (van der Meulen, ) and neuropsychological (Zeman et al, 2010) studies support the theoretical distinction between a visual cache for the temporary storage of visual representations and a system for the generation of visual images, in some models referred to as the visual buffer (Pearson, 2001;Quinn & McConnell, 2006). Logie (1995Logie ( , 2003Logie ( , 2011 In conclusion, our findings suggest that visual STM shows visual interference effects similar to those seen in verbal STM with auditory interference.…”

(A)phantasia and SDAM: Scientific and Personal Perspectives

“…Over time I encountered various other relevant imaging studies such as that of Cui et al (2007), in which fMRI was used in concert with Marks' Vividness of Visual Imagery (VVI) score, and in which individual differences in vividness were quantifiable. Another interesting example is Logie et al (2010) whose work was informed by the Zeman et al (2010) study of Patient MX, who had lost the subjective experience of imagery after an operation, but who retained the ability to perform many of the tasks that he would have previously used it for.…”

“…The publication in early 2015 of the Rotman study was a personal milestone for me, but only a few months later it was followed by a complete surprise-the Zeman et al (2015) paper on Aphantasia in this journal (although I had seen their Zeman et al (2010) study I had never got in contact). One immediate result has been a great increase in the amount of personal testimony on the web about lifetime imagery deficits, from people who recognise aspects of their own experience.…”

Lives without imagery – Congenital aphantasia

“…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 angioplasty (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 account of 'blind imagination', with the important difference that their imagery impairment had been lifelong.…”