Biological Psychology最新文献

Romantic and mother-child relationships are fundamental to human social‑affective functioning. Previous research has consistently shown processing advantages for stimuli associated with both romantic partners and mothers. However, the common and distinct neural and cognitive mechanisms underlying these two central close relationships remain poorly understood. To address this question, the present study combined an associative matching task with electroencephalography (EEG) and computational diffusion modeling to compare perceptual‑decision processes and neural responses to partner‑ versus mother‑associated cues, and to examine their links with self‑reported relationship quality in young adults in romantic relationships (n = 40). During this task, participants were instructed to learn the matching rules between labels (r-partner, mother, self and stranger) and shapes (circle, square, triangle and diamond) and then judged whether the presented shape-label pairings were matched. Both behavioral and EZ‑diffusion modeling analyses showed comparable performance advantages for r-partner and mother stimuli relative to stranger stimuli. Similarly, event‑related potential (ERP) analyses revealed no significant differences between r-partner and mother conditions across early (P100, N200) and middle‑latency (P300) components. Crucially, however, a partner‑specific enhancement was observed in the late positive potential (LPP) relative to stranger, and the magnitude of this LPP bias was positively correlated with self-reported closeness to the r-partner. These results suggest that while romantic and mother‑child relationships engage shared perceptual‑decision mechanisms, romantic intimacy is uniquely associated with a late‑stage evaluative neural signature indexed by the LPP. The findings advance a dual‑process neurocognitive account of close relationships, distinguishing generalized affiliative processing from relationship‑specific motivational evaluation.

Age-related cognitive decline increases the risk of neurodegenerative disorders and contributes to loss of autonomy in older adulthood. The noradrenergic system, particularly the locus coeruleus-noradrenergic (LC-NA) network, plays a crucial role in sustaining cognitive function, and its dysfunction has been implicated in age-related cognitive deterioration. Pupillary responses during cognitively demanding tasks provide a non-invasive index of LC-NA system integrity, as they closely reflect cognitive effort and resource allocation. In the present study, younger and older adults performed an auditory working memory task involving the immediate oral recall of digits sequences of varying lengths (3, 6, or 9-digits) while pupil size was continuously recorded. The data showed that performance declined with increasing sequence length across both groups. However, under higher cognitive load (6 and 9-digit conditions), older adults exhibited significantly reduced pupillary reactivity compared to younger participants. Moreover, pupil dilation correlated with both age and Stroop interference scores, indicating an association between pupillary dynamics and executive (inhibition) control. These findings suggest that although working memory performance was largely preserved in older adults, their attenuated pupillary responses to increasing task demands may reflect early functional alterations in the LC-NA system. Pupillary reactivity thus emerges as a promising, non-invasive biomarker of cognitive control and age-related neural integrity.

Gamma-band brain activity (30-80 Hz) plays a key role in sensory processing and cognitive functioning and is increasingly studied as a potential biomarker for neurological and psychiatric disorders. Recently, Gamma ENtrainment Using Sensory stimulation (GENUS) has emerged as a promising non-invasive approach to modulate this activity, with protocols targeting entrainment of intrinsic neural rhythms. However, substantial methodological variability persists across studies, limiting comparability and reproducibility. To better understand current practices and identify sources of heterogeneity, we reviewed 22 studies investigating gamma-band entrainment through visual, auditory, and multisensory stimulation in healthy adults. We summarized the main stimulation parameters and analytic methods used, discussed critical methodological challenges in evaluating entrainment efficacy, and proposed directions to improve standardization and interpretability. Our findings indicate that sensory modality, stimulus features (i.e., frequency, color), and individual differences shape gamma responses and must be carefully controlled in research and clinical settings. Although 40 Hz is the most frequently used frequency in entrainment studies, optimal effects vary across individuals and brain regions. Spatial patterns of activation also vary: visual stimulation primarily engages occipital-parietal regions, auditory protocols extend to fronto-temporal areas, and multisensory paradigms elicite broader and sometimes superadditive responses. Promising stimulation strategies for enhancing both response strength and participant comfort include invisible flicker, sinusoidal tones, and cross-sensory stimulation. This review highlights important implications for developing therapeutic GENUS protocols and provides guidelines for the stimulation and measurement of gamma responses in experimental and clinical settings.

Physiological synchrony (PS), i.e., the alignment of physiological changes across individuals, is an established phenomenon characterizing social interactions. The degree to which interaction partners synchronize may depend on various relationship- and situation-specific factors. Stress profoundly affects behavior and cognition, but its effect on PS is still unknown. In a preregistered study, we thus investigated the effect of stress on PS in N= 75 romantic couples (mean age = 22.66 ±2.99, 51% female). Partners were separated upon arrival in the laboratory. In n=38 dyads (experimental condition), one partner underwent the Socially Evaluated Cold Pressor Task (SECPT) while the other partner completed a non-stressful control task; in control dyads, both partners underwent the non-stressful task. After completing the intervention separately, partners were reunited and participated in a non-verbal synchronization task, a walking task, and an unstructured social interaction. PS was operationalized by calculating cross-wavelet power of partners' heart rate trajectories. We hypothesized that PS would be altered in couples with one stressed partner compared to the non-stressed control group. Across all interaction tasks, PS was lower in dyads in the experimental than in the control condition. Our findings indicate that stress disrupts PS. In the discussion, we present possible mechanisms for this effect. Our results highlight that stress is not only an intra- but also an interpersonal phenomenon affecting interpersonal physiological processes and social interactions beyond the acute stressor.

Although prior research has demonstrated enhanced striatal response when sharing rewards with close social connections, less is known about how individual differences affect ventral striatal (VS) activation and connectivity when experiencing rewards within social contexts. Given that self-reported reward sensitivity and level of substance use have been associated with differences in VS activation, we set out to investigate whether these factors would be independently associated with enhancements to neural reward responses within social contexts. In this pre-registered study, participants (N = 45) underwent fMRI while playing a card guessing game in which correct or incorrect guesses resulted in monetary gains and losses that were shared evenly with either a close friend, stranger (confederate), or non-human partner. Consistent with our prior work, we found increased VS activation when sharing rewards with a socially close peer as opposed to an out-of-network stranger. As self-reported reward sensitivity increased, the difference in VS response to rewards shared with friends and strangers decreased. We also found enhanced connectivity between the VS and temporoparietal junction when sharing rewards with close friends as opposed to strangers. Finally, exploratory analyses revealed that as reward sensitivity and sub-clinical substance use increase, the difference in VS connectivity with the right fusiform face area increases as a function of social context. These findings demonstrate that responsivity to the context of close friends may be tied to individual reward sensitivity or sub-clinical substance use habits; together these factors may inform predictions of risk for future mental health disorders.

Loneliness is a serious public health issue among the aging population, yet it is not merely an individual but also a relational experience. Indeed, research has shown that having a lonely partner is a "stress generator" with implications for individuals' own biopsychosocial health. Further, widowhood is a stressful and harmful experience in mid and later life, yet no research to date has examined whether the removal of chronic stress posed by a lonely partner via widowhood may be associated with improved biological health following loss. Using blood-based biomarker data from 13,205 continuously partnered and 343 recently widowed adults across two waves of data from the Survey of Health, Ageing, and Retirement in Europe (SHARE; 2013-2015), we examine whether a dyadic partner's loneliness pre-loss is associated with three biological markers of health as well as self-rated health among recent widow(er)s post-loss; whether this differs in comparison with continuously partnered persons over the same timeframe; and whether associations varied by age. Results indicated that (a) deceased dyadic partner's pre-loss loneliness was associated with lower (i.e., healthier) post-loss levels of Cystatin C, a marker of kidney function, among the recently widowed; (b) deceased dyadic partner's pre-loss loneliness was associated with lower (i.e., healthier) post-loss triglyceride levels, a marker of cardiovascular health, but with poorer self-rated health among recent widow(er)s in midlife, yet these effects were attenuated with age; and (c) deceased dyadic partner's pre-loss loneliness was not associated with post-loss levels of C-reactive protein, a marker of inflammation. Interaction terms indicated that these effects were unique to the recently widowed, and did not apply to the continuously partnered. Overall, findings cohere with dyadic biopsychosocial approaches to health, as well as with a role histories approach to studying life transitions. We discuss implications for theory and future research.