No Sensory Compensation for Olfactory Memory: Differences between Blind and Sighted People

Abstract

Blindness can be a driving force behind a variety of changes in sensory systems. When vision is missing, other modalities and higher cognitive functions can become hyper-developed through a mechanism called sensory compensation. Overall, previous studies suggest that olfactory memory in blind people can be better than that of the sighted individuals. Better performance of blind individuals in other-sensory modalities was hypothesized to be a result of, among others, intense perceptual training. At the same time, if the superiority of blind people in olfactory abilities indeed results from training, their scores should not decrease with age to such an extent as among the sighted people. Here, this hypothesis was tested in a large sample of 94 blind individuals. Olfactory memory was assessed using the Test for Olfactory Memory, comprising episodic odor recognition (discriminating previously presented odors from new odors) and two forms of semantic memory (cued and free identification of odors). Regarding episodic olfactory memory, we observed an age-related decline in correct hits in blind participants, but an age-related increase in false alarms in sighted participants. Further, age moderated the between-group differences for correct hits, but the direction of the observed effect was contrary to our expectations. The difference between blind and sighted individuals younger than 40 years old was non-significant, but older sighted individuals outperformed their blind counterparts. In conclusion, we found no positive effect of visual impairment on olfactory memory. We suggest that daily perceptual training is not enough to increase olfactory memory function in blind people.

The Effect of Blindness on Long-Term Episodic Memory for Odors and Sounds

“…This outcome suggests that episodic recognition for olfactory information is unrelated to blindness. Sorokowska and Karwowski (2017) recently showed similar findings for a large sample of blind and sighted participants who were tested shortly after encoding. It should be noted that although the effect of blindness on memory across time differed between the modalities, the interaction effect between retention interval, group, and modality was not statistically significant.…”

Spirituality, silence and solitude: A reflective interpretation regarding mystery and people with nonverbal autism

“…The ability of people with certain disabilities to compensate for their limitations with hyper-developed abilities in other physical and sensory functions is well documented; for example, someone who is visually impaired will often demonstrate acute hearing or better memory (Sorokowska and Karwowski 2017). Relevant to this discussion, differences in the human experience noted in people with nonverbal autism include the response to and processing of sensory stimuli, which manifests as extreme sensitivity to visual, auditory or environmental input (Robertson and Baron-Cohen 2017).…”

Early-blind Individuals Show Impaired Performance in Wine Odor Categorization

“…Indeed, in the case of a forced-choice paradigm, the consensus is that blindness does not affect the performance (Smith et al, 1993;Rosenbluth et al, 2000;Schwenn et al, 2002;Cuevas et al, 2010;Beaulieu-Lefebvre et al, 2011;Luers et al, 2014;Comoglu et al, 2015;Gagnon et al, 2015;Sorokowska, 2016). However, in the case of a free naming identification task, several studies suggest that blind individuals outperform the sighted (Murphy and Cain, 1986;Rosenbluth et al, 2000;Wakefield et al, 2004;Cuevas et al, 2010;Rombaux et al, 2010;Renier et al, 2013;Gagnon et al, 2015), while only one team did not find significant results (Sorokowska, 2016;Sorokowska and Karwowski, 2017). Some authors have suggested that the heightened performance of blind individuals in free odor identification may be explainable by a greater ability for blind individuals to generate words (Burton et al, 2002), rather than from genuine increased olfactory ability.…”