In their integrative memory model, Bastin et al. describe recollection and familiarity as the interaction between core systems, which store specific types of representations, and an attribution system that translates content reactivation into a subjective experience. According to the authors, within these systems, specific types of representations (such as people and things) are uniquely shaped by specific computational operations and are involved in item familiarity. Therefore, these systems build specific memory traces, and damage to them induces severe degradation of these memory traces.

Bastin et al. distinguish the function of various structures included in these systems (i.e., perirhinal cortex, ventral temporopolar cortex, lateral orbitofrontal cortex, and amygdala) but do not mention the difference that, according to some authors (e.g., Gainotti Reference Gainotti2012; Woollams & Patterson Reference Woollams and Patterson2018), could exist between left and right anterior temporal lobes in the processing of verbal and non-verbal representations. However, there is convincing evidence that this lateralization of verbal and non-verbal representations of people and things is reflected in the lateralization of the corresponding familiarity feelings that can be observed in both normal and pathological conditions. This is particularly clear for face familiarity feelings, which are very important in personal interaction, because of the social relevance of distinguishing well-known from unfamiliar people.

A relationship between the right hemisphere and face familiarity feelings has, indeed, been repeatedly demonstrated in healthy subjects, by asking them to make familiarity judgments about faces presented separately to the right and left visual fields, and by studying the lateralization of event-related potentials or of magnetoencephalographic (MEG) waveforms evoked by face familiarity. For instance, Stone and Valentine (Reference Stone and Valentine2005) showed that, when faces were unilaterally presented so briefly that they could not be consciously perceived, the right hemisphere differentiated famous from unfamiliar faces more rapidly than the left hemisphere; and Kloth et al. (Reference Kloth, Dobel, Schweinberger, Zwitserlood, Bölte and Junghöfer2006) suggested that the mechanisms underlying the right hemisphere involvement in face familiarity feelings might primarily concern the early stages of visual processing. Analogously, a selective defect of face familiarity feelings was documented by Gainotti and Marra (Reference Gainotti and Marra2011) in patients with unilateral lesions of the anterior or the posterior parts of the right temporal lobes, who showed a familiar people recognition disorder.

Although a general review of these investigations can be found in Gainotti (Reference Gainotti2007), I more recently expanded the study of the different hemispheric specialization that might concern the representation of different verbal (name) and non-verbal (face and voice) modalities of person identification (Gainotti Reference Gainotti2013). With this aim in mind, I took into account investigations that had evaluated laterality effects in recognition of familiar names, faces, and voices in normal subjects, by means of behavioral, neurophysiological, and neuroimaging techniques. Results of this survey indicated that: (a) recognition of familiar faces and voices shows a prevalent right lateralization, whereas recognition of familiar names is lateralized to the left hemisphere; (b) the right hemisphere prevalence is greater in tasks involving familiar than unfamiliar faces and voices, and the left hemisphere superiority is greater for the recognition of familiar rather than unfamiliar names. Taken together, these data suggest that hemispheric asymmetries in the recognition of faces, voices, and names are not limited to their perceptual processing, but also extend to the domain of their cortical representations.

Also consistent with these general views, but more specifically relevant to the problem of the relations between loss of face familiarity feelings and disruption of the right anterior temporal lobe are the results obtained recently by Borghesani et al. (Reference Borghesani, Narvid, Battistella, Shwe, Watson, Binney, Sturm, Miller, Mandelli, Miller and Gorno-Tempini2019), who studied, in a large sample of patients with neurodegenerative disorders, the neuroanatomical substrates of three different steps of famous-face processing. Using voxel-based morphology, these authors correlated whole-brain gray matter volumes with scores on three experimental tasks that targeted, respectively: (a) familiarity judgment, (b) semantic/biographical information retrieval, and (c) naming. Although performance in naming and semantic information retrieval correlated significantly with gray matter volume in the left anterior temporal lobe, familiarity judgment correlated with the integrity of the right anterior middle temporal gyrus.

Taken together, these findings suggest that computational operations linked to the different formats of representations subsumed by the right and left anterior temporal lobes should be taken into account in a general model which aims to describe the neurocognitive architecture of representations and operations underlying recollection and familiarity.

It could be objected that the integrative memory model aims to understand the organization of episodic memory, whereas the above-surveyed data are more relevant to the organization of semantic rather than episodic memory. However, even leaving apart the interdependence between episodic and semantic memory (e.g., Greenberg & Verfaellie Reference Greenberg and Verfaellie2010), the specific subject of this commentary concerns familiarity for faces that, due to its relevance in social interactions, lies at the border between the episodic and semantic memory systems.