L. Elizabeth Crawford

Loneliness and health: potential mechanisms.

Objective Two studies using cross-sectional designs explored four possible mechanisms by which loneliness may have deleterious effects on health: health behaviors, cardiovascular activation, cortisol levels, and sleep. Methods In Study 1, we assessed autonomic activity, salivary cortisol levels, sleep quality, and health behaviors in 89 undergraduate students selected based on pretests to be among the top or bottom quintile in feelings of loneliness. In Study 2, we assessed blood pressure, heart rate, salivary cortisol levels, sleep quality, and health behaviors in 25 older adults whose loneliness was assessed at the time of testing at their residence. Results Total peripheral resistance was higher in lonely than nonlonely participants, whereas cardiac contractility, heart rate, and cardiac output were higher in nonlonely than lonely participants. Lonely individuals also reported poorer sleep than nonlonely individuals. Study 2 indicated greater age-related increases in blood pressure and poorer sleep quality in lonely than nonlonely older adults. Mean salivary cortisol levels and health behaviors did not differ between groups in either study. Conclusions Results point to two potentially orthogonal predisease mechanisms that warrant special attention: cardiovascular activation and sleep dysfunction. Health behavior and cortisol regulation, however, may require more sensitive measures and large sample sizes to discern their roles in loneliness and health.

Affect biases memory of location : Evidence for the spatial representation of affect

Orientational metaphors that associate good with up and bad with down illustrate that spatial terms can be used to describe positivity and negativity. The present work examined how the association between valence and verticality influences memory for the locations of emotionally evocative stimuli. In two spatial memory experiments, participants viewed positive and negative images from the International Affective Picture System in various locations and then reproduced each images location from memory. Results indicated that memories of location are influenced by stimulus valence, such that positive items are biased upward relative to negative items. A third experiment extended these results to yearbook photos that had been paired with positive or negative behavioural descriptions. The findings suggest that affective responses evoke spatial representations, leading to systematic biases in spatial memory.

Learning Where to Look for Danger: Integrating Affective and Spatial Information

Although not previously addressed by researchers of spatial cognition or affect, the combination of spatial and affective information is essential for many approach and avoidance behaviors, and thus for survival. We provide the first evidence that through incidental experience, people form representations that capture correlations between affective and spatial information. Participants were able to do so even when the correlation was weak, they were not told to look for the correlation, and the stimuli varied on multiple other dimensions besides valence. In addition, people were more sensitive to the presented correlation when stimuli were negative than when they were positive. This asymmetry in representation may stem from underlying differences in the activation functions for positive and negative hedonic information processing.

Conceptual Metaphors of Affect

Emotional experiences are often described in metaphoric language. A major question in linguistics and cognitive science is whether such metaphoric linguistic expressions reflect a deeper principle of cognition. Are abstract concepts structured by the embodied, sensorimotor domains that we use to describe them? This review presents the argument for conceptual metaphors of affect and summarizes recent findings from empirical studies. These findings show that, consistent with the conceptual metaphor account, the associations between affect and physical domains such as spatial position, musical pitch, brightness, and size which are captured in linguistic metaphors also influence performance on attention, memory and judgment tasks. Despite this evidence, a number of concerns with metaphor as an account of affect representation are considered.

Category Effects on Estimates of Stimuli: Perception or Reconstruction?:

The present study examined a common category effect that has been reported in the literature: the tendency for estimates of individual stimuli to be biased toward the central value of the presented set of stimuli. Both encoding and reconstruction accounts of this central-tendency effect are considered. Plain vertical lines and vertical lines embedded in the Müller-Lyer illusion were estimated while still in view or from memory. Although bias due to the Müller-Lyer illusion remained constant across the two conditions, bias due to the context set (category) occurred only when stimuli were estimated from memory. The results suggest that the category bias occurs at a later stage of processing than the Müller-Lyer effect and offer support for a reconstruction account of category effects on stimulus estimation.

Event valence and spatial metaphors of time

Recent research suggests that peoples understanding of the abstract domain of time is dependent on the more concrete domain of space. Boroditsky and Ramscar (2002) found that spatial context influences whether people see themselves as moving through time (ego-moving perspective) or as time moving towards them (time-moving perspective). Based on studies of the embodiment of affective experience, we examined whether affect might also influence which spatial metaphor of time people adopt. The results of Experiments 1 and 2 showed that participants who imagined a negative event were more likely to report that the event was approaching them, whereas those who imagined a positive event were more likely to report that they were approaching the event. Experiments 3a and 3b showed that participants judge an event to be more positive if it is described from the ego-moving perspective than if it is described from the time-moving perspective. Results from these studies provide initial evidence that positive and negative events are associated with different spatial metaphors of time.

Within-category feature correlations and Bayesian adjustment strategies

To the extent that categories inform judgments about items, the accuracy with which categories capture the statistical structure of experience should affect judgment accuracy. The authors argue that representations of feature correlations can serve as Bayesian priors, increasing the accuracy of stimulus estimates by decreasing variability. Participants viewed a series of objects that varied on two dimensions that were either uncorrelated or correlated. They estimated each item by manipulating a response object to make it match the presented stimulus. Subsequent classification and featureinference tasks indicated that the correlation was detected. The pattern of variability in recollections of stimuli suggested that the feature correlation informed estimates as predicted by a Bayesian model of category effects on memory. This work was supported by NIMH Grant 1 F31 MH12072-01A1 to the first author.

Category effects on stimulus estimation: Shifting and skewed frequency distributions

The category adjustment model (CAM) proposes that estimates of inexactly remembered stimuli are adjusted toward the central value of the category of which the stimuli are members. Adjusting estimates toward the average value of all category instances, properly weighted for memory uncertainty, maximizes the average accuracy of estimates. Thus far, the CAM has been tested only with symmetrical category distributions in which the central stimulus value is also the mean. We report two experiments using asymmetric (skewed) distributions in which there is more than one possible central value: one where the frequency distribution shifts over the course of time, and the other where the frequency distribution is skewed. In both cases, we find that people adjust estimates toward the category’s running mean, which is consistent with the CAM but not with alternative explanations for the adjustment of stimuli toward a category’s central value.

Estimating Stimuli from Contrasting Categories: Truncation Due to Boundaries.

In this article, the authors present and test a formal model that holds that people use information about category boundaries in estimating inexactly represented stimuli. Boundaries restrict stimuli that are category members to fall within a particular range. This model posits that people increase the average accuracy of stimulus estimates by integrating fine-grain values with boundary information, eliminating extreme responses. The authors present 4 experiments in which people estimated sizes of squares from 2 adjacent or partially overlapping stimulus sets. When stimuli from the 2 sets were paired in presentation, people formed relative size categories, truncating their estimates at the boundaries of these categories. Truncation at the boundary of separation between the categories led to exaggeration of differences between stimuli that cross categories. Yet truncated values are shown to be more accurate on average than unadjusted values.

Primacy or recency effects in forming inductive categories

Five experiments provide evidence for a primacy effect in the formation of inductive categories. Participants completed a category induction task in which they observed and reproduced a set of lines that varied in length but were serially ordered so that they increased or decreased in length. Subsequent estimates of the average of the distribution were systematically biased in the direction of stimuli encountered at the beginning of the induction task, suggesting that initially encountered stimuli exert greater weight in a category representation than do subsequent stimuli. We offer possible explanations for why this primacy effect might arise.