From lecture transcript to teaching system

Movement can fail in qualitatively distinct ways depending on which component of the motor system is disrupted. This article provides a systematic account of the neural systems supporting voluntary action and the disorders that arise from their dysfunction. Five dimensions of motor impairment are distinguished: failure to generate force, failure to organise a learned action, failure to initiate and scale movement, failure to coordinate movement components, and the intrusion of unwanted activity. Parkinson's disease serves as the primary clinical exemplar, examined through the lens of dopaminergic circuit dysfunction, pharmacological and surgical intervention, and rehabilitation strategies. Contrasting conditions---including amyotrophic lateral sclerosis, Huntington's disease, dystonia, essential tremor, cerebellar ataxia, limb apraxia, and acquired apraxia of speech---are discussed to illustrate how different network disruptions produce different observable syndromes. Cerebellar contributions to prediction, adaptation, and motor learning are addressed alongside the limitations of forward-model accounts. Phantom limb phenomena are presented as evidence for the representational nature of body experience. Throughout, a methodological principle is emphasised: description of the impairment must precede localisation, and localisation must precede causal inference. Accurate phenomenological characterisation is the foundation of both clinical assessment and mechanistic understanding.

Ethnocentrism, broadly defined as the tendency to evaluate other cultures according to the standards and values of one's own culture, represents one of the most pervasive yet underexamined forces shaping human cognition, social behavior, and scientific inquiry. This article, derived from a guest lecture delivered in an introductory psychology course, explores the psychological foundations of ethnocentrism, tracing its origins in basic cognitive processes such as social categorization and socialization, and examining how it can escalate into stereotyping, prejudice, and, in its most extreme form, racism. Particular attention is paid to the distinction between explicit and implicit bias, including the methodological challenges inherent in studying unconscious attitudes. The article further introduces linguistic markers---specifically accent---as an often overlooked yet powerful cue that individuals use to distinguish in-group from out-group members. Drawing on research in both psychology and applied linguistics, including accent bias studies conducted in Pacific educational settings, this overview argues that recognizing and studying ethnocentric tendencies, whether overt or subconscious, is an essential step toward building more equitable societies and producing more methodologically rigorous psychological research.

Biopsychology (biological psychology) investigates how mental life and behavior emerge from biological systems, especially the nervous system. These lecture notes provide an integrated introduction suitable for students and the general public, emphasizing foundational neuroanatomy, neuronal communication, hemispheric specialization, and the logic and limitations of brain-imaging methods. Using common misconceptions (e.g., the claim that humans use only \(\approx 10\%\) of the brain) as an entry point, the notes develop a coherent account of brain energetics, cellular maintenance, and network-level computation. They then examine the neuron as the fundamental signaling unit and synaptic transmission as the mechanism by which learning modifies functional connectivity. Case-based evidence is highlighted through split-brain surgery outcomes, which reveal dissociations between verbal report and perceptual-motor processing and motivate the concept of a left-hemisphere ``interpreter'' that constructs post hoc narratives. Finally, the notes compare major imaging modalities in terms of spatial and temporal resolution, underscoring why methodological constraints shape theoretical claims, and discuss emerging whole-brain recording approaches in model organisms. The overarching goal is to cultivate biologically grounded psychological reasoning: mental processes are not disembodied faculties but activities of living tissue organized into systems that operate continuously, economically, and adaptively.