Detection of simple and pattern regularity violations occurs at different levels of the auditory hierarchy

Auditory deviance detection in humans is indexed by the mismatch negativity (MMN), a component of the auditory evoked potential (AEP) of the electroencephalogram (EEG) occurring at a latency of 100-250 ms after stimulus onset. However, by using classic oddball paradigms, differential responses to regularity violations of simple auditory features have been found at the level of the middle latency response (MLR) of the AEP occurring within the first 50 ms after stimulus (deviation) onset. These findings suggest the existence of fast deviance detection mechanisms for simple feature changes, but it is not clear whether deviance detection among more complex acoustic regularities could be observed at such early latencies. To test this, we examined the pre-attentive processing of rare stimulus repetitions in a sequence of tones alternating in frequency in both long and middle latency ranges. Additionally, we introduced occasional changes in the interaural time difference (ITD), so that a simple-feature regularity could be examined in the same paradigm. MMN was obtained for both repetition and ITD deviants, occurring at 150 ms and 100 ms after stimulus onset respectively. At the level of the MLR, a difference was observed between standards and ITD deviants at the Na component (20-30 ms after stimulus onset), for 800 Hz tones, but not for repetition deviants. These findings suggest that detection mechanisms for deviants to simple regularities, but not to more complex regularities, are already activated in the MLR range, supporting the view that the auditory deviance detection system is organized in a hierarchical manner

Deviance-related responses along the auditory hierarchy: combined FFR, MLR and MMN evidence

The mismatch negativity (MMN) provides a correlate of automatic auditory discrimination in human auditory cortex that is elicited in response to violation of any acoustic regularity. Recently, deviance-related responses were found at much earlier cortical processing stages as reflected by the middle latency response (MLR) of the auditory evoked potential, and even at the level of the auditory brainstem as reflected by the frequency following response (FFR). However, no study has reported deviance-related responses in the FFR, MLR and long latency response (LLR) concurrently in a single recording protocol. Amplitude-modulated (AM) sounds were presented to healthy human participants in a frequency oddball paradigm to investigate deviance-related responses along the auditory hierarchy in the ranges of FFR, MLR and LLR. AM frequency deviants modulated the FFR, the Na and Nb components of the MLR, and the LLR eliciting the MMN. These findings demonstrate that it is possible to elicit deviance-related responses at three different levels (FFR, MLR and LLR) in one single recording protocol, highlight the involvement of the whole auditory hierarchy in deviance detection and have implications for cognitive and clinical auditory neuroscience. Moreover, the present protocol provides a new research tool into clinical neuroscience so that the functional integrity of the auditory novelty system can now be tested as a whole in a range of clinical populations where the MMN was previously shown to be defectiv

Desenvolupament transversal de la competència informacional al segon semestre del Grau de Psicologia.

Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Buscar, seleccionar i gestionar informació especialitzada de manera estratègica, fent ús de diferents tecnologies i fonts d'informació és una de les competències transversals de la UB. Cinc assignatures del segon semestre de Psicologia van elaborar un pla d’actuació per treballar-la coordinadament. Els estudiants que van seguir aquesta formació van obtenir notables resultats quan s'enfrontaven a exercicis pràctics específics (identificació de paraules clau o factors d'impacte), però van mostrar mancances a l’hora de resoldre tasques que requerien la cerca avançada, l’ús de l'estil APA, la identificació de títols de revistes científiques o el coneixement global dels usos i recursos d'informació. No obstant, els estudiants que van rebre la formació van ser lleugerament més competents que els seus companys de darrer curs del grau (que no havien rebut aquesta formació coordinada, però que se'ls hi suposa experiència en cerca documental, atesa les demandes de les diferents assignatures que han cursat). D’altra banda, l'avaluació de la competència informacional no va resultar independent de la resta de competències avaluades ja que va correlacionar positivament, tant en la tasca de defensa oral, com en la puntuació de l'examen final de continguts bàsics de l'assignatura (valors rxy entre 0,09 i 0,18).Buscar, seleccionar i gestionar informació especialitzada de manera estratègica, fent ús de diferents tecnologies i fonts d'informació és una de les competències transversals de la UB. Cinc assignatures del segon semestre de Psicologia van elaborar un pla d’actuació per treballar-la coordinadament. Els estudiants que van seguir aquesta formació van obtenir notables resultats quan s'enfrontaven a exercicis pràctics específics (identificació de paraules clau o factors d'impacte), però van mostrar mancances a l’hora de resoldre tasques que requerien la cerca avançada, l’ús de l'estil APA, la identificació de títols de revistes científiques o el coneixement global dels usos i recursos d'informació. No obstant, els estudiants que van rebre la formació van ser lleugerament més competents que els seus companys de darrer curs del grau (que no havien rebut aquesta formació coordinada, però que se'ls hi suposa experiència en cerca documental, atesa les demandes de les diferents assignatures que han cursat). D’altra banda, l'avaluació de la competència informacional no va resultar independent de la resta de competències avaluades ja que va correlacionar positivament, tant en la tasca de defensa oral, com en la puntuació de l'examen final de continguts bàsics de l'assignatura (valors rxy entre 0,09 i 0,18)

Detection of simple and pattern regularity violations occurs at different levels of the auditory hierarchy

Auditory deviance detection in humans is indexed by the mismatch negativity (MMN), a component of the auditory evoked potential (AEP) of the electroencephalogram (EEG) occurring at a latency of 100-250 ms after stimulus onset. However, by using classic oddball paradigms, differential responses to regularity violations of simple auditory features have been found at the level of the middle latency response (MLR) of the AEP occurring within the first 50 ms after stimulus (deviation) onset. These findings suggest the existence of fast deviance detection mechanisms for simple feature changes, but it is not clear whether deviance detection among more complex acoustic regularities could be observed at such early latencies. To test this, we examined the pre-attentive processing of rare stimulus repetitions in a sequence of tones alternating in frequency in both long and middle latency ranges. Additionally, we introduced occasional changes in the interaural time difference (ITD), so that a simple-feature regularity could be examined in the same paradigm. MMN was obtained for both repetition and ITD deviants, occurring at 150 ms and 100 ms after stimulus onset respectively. At the level of the MLR, a difference was observed between standards and ITD deviants at the Na component (20-30 ms after stimulus onset), for 800 Hz tones, but not for repetition deviants. These findings suggest that detection mechanisms for deviants to simple regularities, but not to more complex regularities, are already activated in the MLR range, supporting the view that the auditory deviance detection system is organized in a hierarchical manner

Deviance-Related Responses along the Auditory Hierarchy: Combined FFR, MLR and MMN Evidence.

The mismatch negativity (MMN) provides a correlate of automatic auditory discrimination in human auditory cortex that is elicited in response to violation of any acoustic regularity. Recently, deviance-related responses were found at much earlier cortical processing stages as reflected by the middle latency response (MLR) of the auditory evoked potential, and even at the level of the auditory brainstem as reflected by the frequency following response (FFR). However, no study has reported deviance-related responses in the FFR, MLR and long latency response (LLR) concurrently in a single recording protocol. Amplitude-modulated (AM) sounds were presented to healthy human participants in a frequency oddball paradigm to investigate deviance-related responses along the auditory hierarchy in the ranges of FFR, MLR and LLR. AM frequency deviants modulated the FFR, the Na and Nb components of the MLR, and the LLR eliciting the MMN. These findings demonstrate that it is possible to elicit deviance-related responses at three different levels (FFR, MLR and LLR) in one single recording protocol, highlight the involvement of the whole auditory hierarchy in deviance detection and have implications for cognitive and clinical auditory neuroscience. Moreover, the present protocol provides a new research tool into clinical neuroscience so that the functional integrity of the auditory novelty system can now be tested as a whole in a range of clinical populations where the MMN was previously shown to be defective

Simple regularity (ITD change): mean amplitudes of the P0, Na, Pa and Nb components of the MLR and the MMN range.

<p>Mean amplitudes (in µV) and standard errors (in parentheses) elicited by standard (std) and deviant (dev) tones for the Na component of the MLR and the MMN range at the Fz electrode. Note that standard tones for the simple regularity correspond to the standard tones in the reverse block, which had the same physical characteristics as the deviants in the tone-alternation sequence. Asterisks indicate significant differences between standard and deviant responses [*<i>p</i><0.05; **<i>p</i><0.001].</p

AEPs for the pattern regularity.

<p>Grand average evoked potentials (N = 24) elicited by standard tones (grey lines), and deviant tones (black lines) at the Fz electrode. The upper and lower rows show the responses to the 800 and 650 Hz tones, respectively. A) Waveforms in the MLR range. B) Waveforms in the MMN range. Dashed lines show the MMN elicited by the repetition deviants. The grey bars denote the windows of measurement. [*<i>p</i><0.001].</p

Scalp topographies for the simple regularity (ITD change).

<p>A) Long-latency responses (90–130 ms time window) to the standard tones of the reverse block, the deviant tones and the MMN. B) MLR responses at Na (21–25 ms time window) to the standard tones of the reverse block, the deviant tones and their difference (deviant-standard).</p

Experimental design.

<p>A) Tone-alternation sequence. B) Reverse block. Letters <i>C</i> (center) and <i>L (</i>left) indicate the perceived location of the sound for standards (in black), and deviants (in grey).</p