Lambda potential in the rhesus monkey

Abstract

Averaged lambda potentials associated with saccadic eye movements were studied in five rhesus monkeys. The influence of field luminance and of saccade size on the latency/amplitude of potentials recorded transcortica1ly from within primary visual cortex were analyzed. Decrease in the luminance of the stimulus field led to a decrease in the amplitude of the first prominent negative component (N,) and to a lengthening of the late positive component (P3). Saccade size had a different influence on the N, and P 3 components. N, latency from saccade onset changed only slightly with increase in saccade size. P 3 latency, on the other hand, increased significantly when measured from saccade onset, but showed no latency differences with saccade sizes when measured from saccade offset. These results support the conclusion drawn from human studies as well that the N, component is related to events at the onset of and during saccades (e.g., suppression), whereas P3 is linked to saccade offset and reflects information pickup in a new fixation.

Comparison between the lambda response of eye-fixation-related potentials and the P100 component of pattern-reversal visual evoked potentials

“…Therefore, the lambda response is believed to be elicited by the afferent inflow beginning at the fixation pause, since visual suppression (e.g., Volkmann, 1986) occurs during saccades. Yagi's (1979) finding was confirmed by other studies (Billings, 1989;Szirtes et al, 1982;Thickbroom et al, 1991;Yagi, 1981a).…”

“…EFRPs are nearly synonymous with the lambda complex (Lesèvre & Rémond, 1973;Szirtes, Marton, & Breuer, 1982;Yagi, 1979) or the lambda wave (Billings, 1989;Kurtzberg & Vaughan, 1973;Morton, Merton, & Cobb, 1974;Thickbroom, Knezevic, Carroll, & Mastaglia, 1991). The most prominent component of the EFRP is called the lambda response, which is a sharp positive component with a latency of about 80 msec from the offset of saccades.…”

Lambda Response by Orientation of Striped Patterns

“…Yagi (1979Yagi ( , 1981a found that the lambda response was linked to the offset of the saccade, i.e., the onset of eye-fixation, rather than to the onset of the saccade (Scott, Moffett, & Bickford, 1981). Other studies also support his findings (Szirtes, Marton, & Breuer, 1982;Billings, 1989;Jagla & Z h u n d , 1994). Therefore, based on the finding that threshold of visual inputs increases during saccades (Zuber & Stark, 1966;Matin, 1974;Vollcrnann, 1986), the lambda response had been thought to be evoked by the inflow of visual information after the termination of the saccade.…”

Source Localization of Normal Variants Seen on EEG

“…The results obtained are concordant with previous studies using animal model and invasive EEG recordings. [4][5][6] In this article, we used advanced source localization techniques for different normal variants with each normal variant assessed in multiple individuals as shown in the flow diagram (Fig. 4).…”

“…[1][2][3] In the past, multiple animal studies, as well as invasive EEG data, have shed light on these variants. [4][5][6] Although the established information regarding these variants have reached consensus, there is an ongoing need to better characterize these findings, so that they are not mislabeled as abnormal. More recently, normal variants in EEG have been analyzed via the magnetoencephalogram, which highlights differences in neuronal activity measured via a magnetic source compared with the scalp EEG data used in source localization.…”