Search results for " Mismatch negativity"

Visual mismatch negativity (vMMN): A review and meta-analysis of studies in psychiatric and neurological disorders

2016

The visual mismatch negativity (vMMN) response is an event-related potential (ERP) component, which is automatically elicited by events that violate predictions based on prior events. VMMN experiments use visual stimulus repetition to induce predictions, and vMMN is obtained by subtracting the response to rare unpredicted stimuli from those to frequent stimuli. One increasingly popular interpretation of the mismatch response postulates that vMMN, similar to its auditory counterpart (aMMN), represents a prediction error response generated by cortical mechanisms forming probabilistic representations of sensory signals. Here we discuss the physiological and theoretical basis of vMMN and review…

Dysfunction of attention switching networks in amyotrophic lateral sclerosis

2019

Objective To localise and characterise changes in cognitive networks in Amyotrophic Lateral Sclerosis (ALS) using source analysis of mismatch negativity (MMN) waveforms. Rationale The MMN waveform has an increased average delay in ALS. MMN has been attributed to change detection and involuntary attention switching. This therefore indicates pathological impairment of the neural network components which generate these functions. Source localisation can mitigate the poor spatial resolution of sensor-level EEG analysis by associating the sensor-level signals to the contributing brain sources. The functional activity in each generating source can therefore be individually measured and investigat…

Visual mismatch negativity (vMMN): a prediction error signal in the visual modality

2015

Frontiers in Human Neuroscience, 8

Somatosensory change detection in the aging brain

2011

The study examined the brain’s automatic somatosensory change detection mechanism using event-related potentials (ERPs) to tactile electrical pulses to fingers in an oddball paradigm. Also the effects of aging to these ERPs were investigated comparing the data of young adults (N = 20, 22–27 years) with the data of aged participants (N = 12, 67–95 years). In the experiment, the participants were instructed to ignore finger stimuli and to be fully involved to a radio play during the electroencephalogram (EEG) recording. The electrical stimulation was delivered to participant’s forefinger and little finger in randomized order of standard (P = 0.85) and deviant (P = 0.15) stimuli. The analyzed …

Brief psychological intervention for depression : an ERP study

2009

Brain's change detection elicited by emotional facial expressions in depressed and non-depressed individuals

2009

Detrimental noise effects on brain's speech functions.

2009

Background noise has become part of our everyday life in modern societies. Its presence affects both the ability to concentrate and communicate. Some individuals, like children, the elderly, and non-native speakers have pronounced problems in noisy environments. Here we review evidence suggesting that background noise has both transient and Sustained detrimental effects on central speech processing. Studies on the effects of noise on neural processes have demonstrated hemispheric reorganization in speech processing in adult individuals during background noise. During noise, the well-known left hemisphere dominance in speech discrimination became right hemisphere preponderant. Furthermore, l…

Event-related potentials to unattended changes in facial expressions: detection of regularity violations or encoding of emotions?

2013

Visual mismatch negativity (vMMN), a component in event-related potentials (ERPs), can be elicited when rarely presented “deviant” facial expressions violate regularity formed by repeated “standard” faces. vMMN is observed as differential ERPs elicited between the deviant and standard faces. It is not clear, however, whether differential ERPs to rare emotional faces interspersed with repeated neutral ones reflect true vMMN (i.e., detection of regularity violation) or merely encoding of the emotional content in the faces. Furthermore, a face-sensitive N170 response, which reflects structural encoding of facial features, can be modulated by emotional expressions. Owing to its similar latency …

Explicit behavioral detection of visual changes develops without their implicit neurophysiological detectability

2012

Change blindness is a failure of reporting major changes across consecutive images if separated, e.g., by a brief blank interval. Successful change detection across interrupts requires focal attention to the changes. However, findings of implicit detection of visual changes during change blindness have raised the question of whether the implicit mode is necessary for development of the explicit mode. To this end, we recorded the visual mismatch negativity (vMMN) of the event-related potentials (ERPs) of the brain, an index of implicit pre-attentive visual change detection, in adult humans performing an oddball-variant of change blindness flicker task. Images of 500 ms in duration were prese…

Brain's capacity to detect abstract regularities from visual stimuli under different attentive conditions- an ERP study

2010

Many previous studies have applied oddball paradigm to study change detection. Although changes within single features have been investigated a lot, the changes in multiple feature conjunctions have not. The aim of our study was to investigate with event-related potentials by applying oddball paradigm, whether the brain can detect abstract regularities in visual stimulus stream when two different features are combined - semantic meaning and color. Participants were shown adjective words written in red and blue print in quasi-random order on a computer screen. In an oddball paradigm, 90 % of the words (‘standard’) followed the rule “words printed in red have a negative meaning and the words …