Alignment of Continuous Auditory and Visual Distractor Stimuli Is Leading to an Increased Performance

Information across different senses can affect our behavior in both positive and negative ways. Stimuli aligned with a target stimulus can lead to improved behavioral performances, while competing, transient stimuli often negatively affect our task performance. But what about subtle changes in task-irrelevant multisensory stimuli? Within this experiment we tested the effect of the alignment of subtle auditory and visual distractor stimuli on the performance of detection and discrimination tasks respectively. Participants performed either a detection or a discrimination task on a centrally presented Gabor patch, while being simultaneously subjected to a random dot kinematogram, which alternated its color from green to red with a frequency of 7.5 Hz and a continuous tone, which was either a frequency modulated pure tone for the audiovisual congruent and incongruent conditions or white noise for the visual control condition. While the modulation frequency of the pure tone initially differed from the modulation frequency of the random dot kinematogram, the modulation frequencies of both stimuli could align after a variable delay, and we measured accuracy and reaction times around the possible alignment time. We found increases in accuracy for the audiovisual congruent condition suggesting subtle alignments of multisensory background stimuli can increase performance on the current task

Was bringen Vernetzung und Kooperation für die lokale Wirtschaftsentwicklung? - Bericht über eine Tagung am IWH

The Department of Urban Economics of the Halle Institute for Economic Research (IWH) held on 2 and 3 December 2010 the third “Halle Forum on Urban Economic Growth“. The biennial “Halle Forum” focuses on the determinants of urban growth. This year's conference addressed the forms and benefits of cooperation and networking for the economic development of cities and metropolitan regions. The presentations and discussions focused on the one hand on the effects and determinants of inter-and intra-regional cooperation between firms, and on the other hand on cooperation between neighboring municipalities, especially through the establishment of metropolitan regions.

Cross-frequency phase-amplitude coupling in repetitive movements in patients with Parkinson’s disease

Bradykinesia is a cardinal motor symptom in Parkinson’s disease whose pathophysiology is incompletely understood. When signals are recorded from the cortex or scalp at rest, affected patients display enhanced phase-amplitude coupling between β (13-30Hz) and broadband γ (50-150Hz) oscillatory activities. However, it remains unclear whether and how abnormal phase-amplitude coupling is involved in slowing Parkinsonian movements during their execution. To address these questions, we analyzed high-density EEG signals recorded simultaneously with various motor activities and at rest in 19 patients with Parkinson’s disease and 20 healthy controls. The motor tasks consisted of repetitive index finger pressing, and slow and fast tapping movements. Individual EEG source signals were computed for the premotor cortex, primary motor cortex, primary somatosensory cortex, and primary somatosensory complex. For the resting condition and the pressing task, phase-amplitude coupling averaged over the 4 motor regions and the entire movement period was larger in patients than in controls. In contrast, in all tapping tasks, state-related phase-amplitude coupling was similar between patients and controls. These findings were not aligned with motor performance and EMG data, which showed abnormalities in patients for tapping but not for pressing, suggesting that the strength of β-broadband γ phase-amplitude coupling during the movement period does not directly relate to Parkinsonian bradykinesia. Subsequently, we examined the dynamics of oscillatory EEG signals during motor transitions. When healthy controls performed the pressing task, dynamic phase-amplitude coupling increased shortly before pressing onset and decreased subsequently. A strikingly similar motif of coupling rise and decay was observed around the offset of pressing and around the onset of slow tapping, suggesting that such transient phase-amplitude coupling changes may be linked to transitions between different movement states – akin to preparatory states in dynamical systems theory of motor control. In patients, the modulation of phase-amplitude coupling was similar in (normally executed) pressing, but flattened in slow (abnormally executed) tapping compared to the controls. These deviations in phase-amplitude coupling around motor action transients may indicate dysfunctional evolution of neuronal population dynamics from the preparatory state to movement generation in Parkinson’s disease. These findings may indicate that cross-frequency coupling is involved in the pathophysiology of bradykinesia in Parkinson’s disease through its abnormal dynamic modulation

Cross-frequency phase-amplitude coupling in repetitive movements in patients with Parkinson’s disease

Bradykinesia is a cardinal motor symptom in Parkinson's disease (PD), the pathophysiology of which is not fully understood. We analyzed the role of cross-frequency coupling of oscillatory cortical activity in motor impairment in patients with PD and healthy controls. High-density EEG signals were recorded during various motor activities and at rest. Patients performed a repetitive finger-pressing task normally, but were slower than controls during tapping. Phase-amplitude coupling (PAC) between β (13-30 Hz) and broadband γ (50-150 Hz) was computed from individual EEG source signals in the premotor, primary motor, and primary somatosensory cortices, and the primary somatosensory complex. In all four regions, averaging the entire movement period resulted in higher PAC in patients than in controls for the resting condition and the pressing task (similar performance between groups). However, this was not the case for the tapping tasks where patients performed slower. This suggests the strength of state-related β-γ PAC does not determine Parkinsonian bradykinesia. Examination of the dynamics of oscillatory EEG signals during motor transitions revealed a distinctive motif of PAC rise and decay around press onset. This pattern was also present at press offset and slow tapping onset, linking such idiosyncratic PAC changes to transitions between different movement states. The transition-related PAC modulation in patients was similar to controls in the pressing task but flattened during slow tapping, which related to normal and abnormal performance, respectively. These findings suggest that the dysfunctional evolution of neuronal population dynamics during movement execution is an important component of the pathophysiology of Parkinsonian bradykinesia.NEW & NOTEWORTHY Our findings using noninvasive EEG recordings provide evidence that PAC dynamics might play a role in the physiological cortical control of movement execution and may encode transitions between movement states. Results in patients with Parkinson's disease suggest that bradykinesia is related to a deficit of the dynamic regulation of PAC during movement execution rather than its absolute strength. Our findings may contribute to the development of a new concept of the pathophysiology of bradykinesia

Symbolic Object Code Analysis

Current software model checkers quickly reach their limit when being applied to verifying pointer safety properties in source code that includes function pointers and inlined assembly. This paper introduces an alternative technique for checking pointer safety violations, called Symbolic Object Code Analysis (SOCA), which is based on bounded symbolic execution, incorporates path-sensitive slicing, and employs the SMT solver Yices as its execution and verification engine. Extensive experimental results of a prototypic SOCA Verifier, using the Verisec suite and almost 10,000 Linux device driver functions as benchmarks, show that SOCA performs competitively to current source-code model checkers and that it also scales well when applied to real operating systems code and pointer safety issues. SOCA effectively explores semantic niches of software that current software verifiers do not reach

Alignment of Continuous Auditory and Visual Distractor Stimuli Is Leading to an Increased Performance

Information across different senses can affect our behavior in both positive and negative ways. Stimuli aligned with a target stimulus can lead to improved behavioral performances, while competing, transient stimuli often negatively affect our task performance. But what about subtle changes in task-irrelevant multisensory stimuli? Within this experiment we tested the effect of the alignment of subtle auditory and visual distractor stimuli on the performance of detection and discrimination tasks respectively. Participants performed either a detection or a discrimination task on a centrally presented Gabor patch, while being simultaneously subjected to a random dot kinematogram, which alternated its color from green to red with a frequency of 7.5 Hz and a continuous tone, which was either a frequency modulated pure tone for the audiovisual congruent and incongruent conditions or white noise for the visual control condition. While the modulation frequency of the pure tone initially differed from the modulation frequency of the random dot kinematogram, the modulation frequencies of both stimuli could align after a variable delay, and we measured accuracy and reaction times around the possible alignment time. We found increases in accuracy for the audiovisual congruent condition suggesting subtle alignments of multisensory background stimuli can increase performance on the current task

Alignment of Continuous Auditory and Visual Distractor Stimuli Is Leading to an Increased Performance

Information across different senses can affect our behavior in both positive and negative ways. Stimuli aligned with a target stimulus can lead to improved behavioral performances, while competing, transient stimuli often negatively affect our task performance. But what about subtle changes in task-irrelevant multisensory stimuli? Within this experiment we tested the effect of the alignment of subtle auditory and visual distractor stimuli on the performance of detection and discrimination tasks respectively. Participants performed either a detection or a discrimination task on a centrally presented Gabor patch, while being simultaneously subjected to a random dot kinematogram, which alternated its color from green to red with a frequency of 7.5 Hz and a continuous tone, which was either a frequency modulated pure tone for the audiovisual congruent and incongruent conditions or white noise for the visual control condition. While the modulation frequency of the pure tone initially differed from the modulation frequency of the random dot kinematogram, the modulation frequencies of both stimuli could align after a variable delay, and we measured accuracy and reaction times around the possible alignment time. We found increases in accuracy for the audiovisual congruent condition suggesting subtle alignments of multisensory background stimuli can increase performance on the current task