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1.
J Vis ; 24(4): 8, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38591941

RESUMEN

Older adults show decline in visual search performance, but the underlying cause remains unclear. It has been suggested that older adults' altered performance may be related to reduced spatial attention to peripheral visual information compared with younger adults. In this study, 18 younger (M = 21.6 years) and 16 older (M = 69.1 years) participants performed pop-out and serial visual search tasks with variously sized gaze-contingent artificial central scotomas (3°, 5°, or 7° diameter). By occluding central vision, we measured how attention to the periphery was contributing to the search performance. We also tested the effect of target eccentricity on search times and eye movements. We hypothesized that, if attention is reduced primarily in the periphery in older adults, we would observe longer search times for more eccentric targets and with central occlusion. During the pop-out search, older adults showed a steeper decline in search performance with increasing eccentricity and central scotoma size compared with younger adults. In contrast, during the serial search, older adults had longer search times than younger adults overall, independent of target eccentricity and scotoma size. Longer search times were attributed to higher cost-per-item slopes, indicating increased difficulty in simultaneously processing complex symbols made up of separable features in aging, possibly stemming from challenges in spatially binding individual features. Altogether, our findings point to fewer attentional resources of simultaneous visual processing to distribute over space or separable features of objects, consistent with decreased dorsal visual stream functioning in aging.


Asunto(s)
Envejecimiento , Movimientos Oculares , Humanos , Anciano , Escotoma , Percepción Visual
2.
J Vis ; 21(8): 8, 2021 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-34347017

RESUMEN

Trans-saccadic memory consists of keeping track of objects' locations and features across saccades; pre-saccadic information is remembered and compared with post-saccadic information. It has been shown to have limited resources and involve attention with respect to the selection of objects and features. In support, a previous study showed that recognition of distinct post-saccadic objects in the visual scene is impaired when pre-saccadic objects are relevant and thus already encoded in memory (Poth, Herwig, Schneider, 2015). Here, we investigated the inverse (i.e. how the memory of pre-saccadic objects is affected by abrupt but irrelevant changes in the post-saccadic visual scene). We also modulated the amount of attention to the relevant pre-saccadic object by having participants either make a saccade to it or elsewhere and observed that pre-saccadic attentional facilitation affected how much post-saccadic changes disrupted trans-saccadic memory of pre-saccadic objects. Participants identified a flashed symbol (d, b, p, or q, among distracters), at one of six placeholders (figures "8") arranged in circle around fixation while planning a saccade to one of them. They reported the identity of the symbol after the saccade. We changed the post-saccadic scene in Experiment one by removing the entire scene, only the placeholder where the pre-saccadic symbol was presented, or all other placeholders except this one. We observed reduced identification performance when only the saccade-target placeholder disappeared after the saccade. In Experiment two, we changed one placeholder location (inward/outward shift or rotation re. saccade vector) after the saccade and observed that identification performance decreased with increased shift/rotation of the saccade-target placeholder. We conclude that pre-saccadic memory is disrupted by abrupt attention-capturing post-saccadic changes of visual scene, particularly when these changes involve the object prioritized by being the goal of a saccade. These findings support the notion that limited trans-saccadic memory resources are disrupted when object correspondence at saccadic goal is broken through removal or location change.


Asunto(s)
Movimientos Sacádicos , Humanos
3.
Early Interv Psychiatry ; 15(4): 753-761, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-32578401

RESUMEN

AIM: To assess the feasibility, acceptability and potential impact of a cognitive behavioural group intervention occurring over 12 sessions and focusing on romantic relationships for single men with early psychosis. METHODS: Recruitment, drop-out and participation rates were collected. An A-B-A within-subject design (n = 7), where each participant acted as his own control, was used to determine potential impact (on social functioning, romantic relationship functioning, self-esteem, theory of mind [ToM] and self-stigma) across time (six time points). RESULTS: Feasibility and acceptability were established. As for the potential impact of the intervention, participants did not all evolve the same way. Improvements were found on social functioning ("behaviours" subscale), romantic relationship functioning and ToM ("mentalizing" subscale). CONCLUSIONS: More studies are warranted to expand on these results and to further help men with early psychosis in their social and romantic development.


Asunto(s)
Terapia Cognitivo-Conductual , Trastornos Psicóticos , Estudios de Factibilidad , Humanos , Masculino , Proyectos Piloto , Trastornos Psicóticos/terapia , Autoimagen
4.
Restor Neurol Neurosci ; 38(3): 203-222, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32675431

RESUMEN

BACKGROUND: Central vision loss, such as in the case of age-related macular degeneration (AMD), has a a major negative impact on patients' quality of life. However, some patients have shown spontaneous adaptive strategies development, mostly relying on their peripheral vision. OBJECTIVE: This study assesses eye movement and eccentric visual function adaptive behaviors of a healthy population in the presence of simulated central vision loss. We wished to determine how central vision loss affects eye movements, specifically the foveal-target alignment. METHODS: Fifteen healthy participants (7 females, M = 21.69, SD = 2.13) discriminated the orientation of a Gabor relative to the vertical located at 12 deg of eccentricity to the right of fixation, in the presence of a gaze-contingent artificial central scotoma either visible or invisible. The artificial central scotoma was 4° diameter in order to simulate an earlier stage of degenerative disease while still impairing foveal vision. The target's orientation varied between 10° counter-clockwise and 10° clockwise. Each participant performed four blocks of 75 trials each per day over 10 days, the first day being a baseline without scotoma. RESULTS: We found changes in the endpoints of the 1st saccade over the practice days. The most common pattern was a gradual upward shift. We also observed a significant increase in discrimination performance over the 9 days of practice. We did not find any difference linked to the scotoma types. CONCLUSIONS: These findings suggest that the presence of an artificial central scotoma combined with a challenging discrimination task induces both changes in saccade planning mechanisms, resulting in a new eccentric-target alignment, and improvements in eccentric visual functions. This demonstrates the potential of this research paradigm to understand and potentially improve visual function in patients with central vision loss.


Asunto(s)
Movimientos Oculares/fisiología , Escotoma/fisiopatología , Agudeza Visual/fisiología , Campos Visuales/fisiología , Adulto , Femenino , Humanos , Degeneración Macular/fisiopatología , Masculino , Calidad de Vida , Pruebas del Campo Visual , Adulto Joven
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