Npgrj_nn_1518 1248..1254
نویسندگان
چکیده
The constructive nature of perception can be demonstrated under viewing conditions that lead to vivid subjective impressions in the absence of direct input. When a low-contrast moving grating is divided by a large gap, observers report seeing a ‘visual phantom’ of the real grating extending through the blank gap region. Here, we report fMRI evidence showing that visual phantoms lead to enhanced activity in early visual areas that specifically represent the blank gap region. We found that neural filling-in effects occurred automatically in areas V1 and V2, regardless of where the subject attended. Moreover, when phantom-inducing gratings were paired with competing stimuli in a binocular rivalry display, subjects reported spontaneous fluctuations in conscious perception of the phantom accompanied by tightly coupled changes in early visual activity. Our results indicate that phantom visual experiences are closely linked to automatic filling-in of activity at the earliest stages of cortical processing.
منابع مشابه
Embryonic Mortality and Chromosomal Alterations Caused by Aroclor 1254 in Ring Doves
The breeding success of Ring Doves (Streptopelia risoria) fed Aroclor 1254 at 10 ppm was determined over two generations. Six pairs of birds were fed PCBs for three months, then allowed to incubate their clutch of two eggs. Eggs were then collected again for six months, at which time the birds were allowed to incubate another clutch. Results are given in Table 1. The low-hatching success of the...
متن کاملToxicities of PCBs to Fish and Environmental Residues
Polychlorinated biphenyls (PCBs) have been found in fish and wildlife from many parts of the world at levels which may adversely affect aquatic organisms and interfere with pesticide residue analyses (1, 2, 3, 4). The environmental occurrence, uses, and present toxicological aspects of PCBs were recently reviewed by Peakall and Lincer (5), Gustaffson (6), and Risebrough (7). PCBs have gas chrom...
متن کاملComplete PCB Congener Distributions for 17 Aroclor Mixtures Determined by 3 HRGC Systems Optimized for Conlprehensive, Quantitative, Congener-Specific Analysis
Three HRGC systems (1: 30m DB-XLB capillary with MS-SIM detection; 2: 60m DB-XLB capillary with full-scan, ion.trap MS detection; and 3: Parallel dual·column DB·17 and series-coupled HP5IHT5 with ECD detection) were used to completely charac· terize multiple lots of 8 different·numbered Aroclor mixtures by quantitative calibration against 9 solutions containing primary standards of all 209 PCB ...
متن کاملDevelopment of a multianalyte enzyme-linked immunosorbent assay for permethrin and aroclors and its implementation for analysis of soil/sediment and house dust extracts.
Development of a multianalyte enzyme-linked immunosorbent assay (ELISA) for detection of permethrin and aroclors 1248 or 1254 and implementation of the assay for analysis of soil/sediment samples are described. The feasibility of using the multianalyte ELISA to monitor aroclors 1254 and permethrin simultaneously was tested with permethrin and aroclor standards and with aroclor- and permethrin-c...
متن کاملPraxis: a Paradigm for Action Research
Action research is a research methodology with a dual purpose (action and research). Action research as other research approach is led through a paradigm or a philosophical perspective. This article briefly describes paradigm, research paradigm and discuss about “which paradigm (positivism, interpretive, or praxis) does cover action research?”.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005