Getting connected: Both associative and semantic links structure semantic memory for newly learned persons

Face-evoked thoughts

The thoughts that come to mind when viewing a face depend partly on the face and partly on the viewer. This basic interaction raises the question of how much common ground there is in face-evoked thoughts, and how this compares to viewers' expectations. Previous analyses have focused on early perceptual stages of face processing. Here we take a more expansive approach that encompasses later associative stages. In Experiment 1 (free association), participants exhibited strong egocentric bias, greatly overestimating the extent to which other people's thoughts resembled their own. In Experiment 2, we show that viewers' familiarity with a face can be decoded from their face-evoked thoughts. In Experiment 3 (person association), participants reported who came to mind when viewing a face-a task that emphasises connections in a social network rather than nodes. Here again, viewers' estimates of common ground exceeded actual common ground by a large margin. We assume that a face elicits much the same thoughts in other people as it does in us, but that is a mistake. In this respect, we are more isolated than we think.

An Analysis of Famous Person Semantic Memory in Aging

BACKGROUND

In contrast to most memory systems that decline with age, semantic memory tends to remain relatively stable across the life span. However, what exactly is stable remains unclear. Is it the quantity of information available or the organization of semantic memory, i.e., the connections between semantic items? Even less is known about semantic memory for celebrities, a subsystem of semantic memory. In the present study, we studied the organization of person-specific semantic memory and its stability in aging.

METHODS

We designed a word association task based on a previous study, which consisted in providing the first word that came to the mind of the participants (15 participants for each age group 20-30, 40-50 and 60-70 years old) for 144 celebrities. We developed a new taxonomy of associated responses as the responses associated with celebrities name could in principle be very varied.

RESULTS

We found that most responses (>90%) could be grouped into five categories (subjective; superordinate general; superordinate specific; imagery and activities). The elderly group did not differ from the other two groups in term of errors or reaction time suggesting they performed the task well. However, they also provided associations that were less precise and less based on imagery. In contrast, the middle-age group provided the most precise associations.

CONCLUSION

These results support the idea of a durable person-specific semantic memory in aging but show changes in the type of associations that elders provide. Future work should aim at studying patients with early semantic impairment, as they could be different from the healthy elders on such semantic association task.

Elements of person knowledge: Episodic recollection helps us to identify people but not to recognize their faces

Faces automatically draw attention, allowing rapid assessments of personality and likely behaviour. How we respond to people is, however, highly dependent on whether we know who they are. According to face processing models person knowledge comes from an extended neural system that includes structures linked to episodic memory. Here we use scalp recorded brain signals to demonstrate the specific role of episodic memory processes during face processing. In two experiments we recorded Event-Related Potentials (ERPs) while participants made identify, familiar or unknown responses to famous faces. ERPs revealed neural signals previously associated with episodic recollection for identify but not familiar faces. These findings provide novel evidence suggesting that recollection is central to face processing, providing one source of person knowledge that can be used to moderate the initial impressions gleaned from the core neural system that supports face recognition.

The N400 reveals how personal semantics is processed: Insights into the nature and organization of self-knowledge

There is growing recognition that some important forms of long-term memory are difficult to classify into one of the well-studied memory subtypes. One example is personal semantics. Like the episodes that are stored as part of one's autobiography, personal semantics is linked to an individual, yet, like general semantic memory, it is detached from a specific encoding context. Access to general semantics elicits an electrophysiological response known as the N400, which has been characterized across three decades of research; surprisingly, this response has not been fully examined in the context of personal semantics. In this study, we assessed responses to congruent and incongruent statements about people's own, personal preferences. We found that access to personal preferences elicited N400 responses, with congruency effects that were similar in latency and distribution to those for general semantic statements elicited from the same participants. These results suggest that the processing of personal and general semantics share important functional and neurobiological features.