Interkey timing in piano performance and typing

Aggregate context effects in music processing

Control of stimulus confounds is an ever-present, and ever-important, aspect of experimental design. Typically, researchers concern themselves with such control on a local level, ensuring that individual stimuli contain only the properties they intend for them to represent. Significantly less attention, however, is paid to stimulus properties in the aggregate, aspects that, although not present in individual stimuli, can nevertheless become emergent properties of the stimulus set when viewed in total. This paper describes two examples of such effects. The first (Case Study 1) focuses on emergent properties of pairs of to-be-performed tones on a piano keyboard, and the second (Case Study 2) focuses on emergent properties of short, atonal melodies in a perception/memory task. In both cases these sets of stimuli induced identifiable tonal influences despite being explicitly created to be devoid of musical tonality. These results highlight the importance of monitoring aggregate stimulus properties in one's research, and are discussed with reference to their implications for interpreting psychological findings quite generally.

Tonal and textural influences on musical sight-reading

Two experiments investigated the impact of two structural factors-musical tonality and musical texture-on pianists' ability to play by sight without prior preparation, known as musical sight-reading. Tonality refers to the cognitive organization of tones around a central reference pitch, whereas texture refers to the organization of music in terms of the simultaneous versus successive onsets of tones as well as the number of hands (unimanual versus bimanual) involved in performance. Both experiments demonstrated that tonality and texture influenced sight-reading. For tonality, both studies found that errors in performance increased for passages with lesser perceived psychological stability (i.e., minor and atonal passages) relative to greater perceived stability (i.e., major passages). For texture, both studies found that errors in performance increased for passages that were more texturally complex, requiring two-handed versus one-handed performance, with some additional evidence that the relative simultaneity of note onsets (primarily simultaneous versus primarily successive) also influenced errors. These experiments are interpreted within a perception-action framework of music performance, highlighting influences of both top-down cognitive factors and bottom-up motoric processes on sight-reading behavior.

Age-related changes in multi-finger interactions in adults during maximum voluntary finger force production tasks

This study aimed to continue our characterization of finger strength and multi-finger interactions across the lifespan to include those in their 60s and older. Building on our previous study of children, we examined young and elderly adults during isometric finger flexion and extension tasks. Sixteen young and 16 elderly, gender-matched participants produced maximum force using either a single finger or all four fingers in flexion and extension. The maximum voluntary finger force (MVF), the percentage contributions of individual finger forces to the sum of individual finger forces during four-finger MVF task (force sharing), and the non-task finger forces during a task finger MVF task (force enslaving), were computed as dependent variables. Force enslaving during finger extension was greater than during flexion in both young and elderly groups. The flexion-extension difference was greater in the elderly than the young adult group. The greater independency in flexion may result from more frequent use of finger flexion in everyday manipulation tasks. The non-task fingers closer to a task finger produced greater enslaving force than non-task fingers farther from the task finger. The force sharing pattern was not different between age groups. Our findings suggest that finger strength decreases over the aging process, finger independency for flexion increases throughout development, and force sharing pattern remains constant across the lifespan.

Effector dependent sequence learning in the serial RT task

At least five earlier studies could not find effector-dependent learning in the keying version of the serial reaction time (RT) task. Experiment 1 examined whether effector-dependent learning occurs when participants practice the serial RT task with three fingers of one hand for about 1,300 sequence repetitions instead of the more common 50-100 repetitions. The results confirm that, following extended practice, sequence learning produces an effector-dependent component. Specifically, an unpracticed hand executed a practiced sequence slower than a practiced hand. However, Experiment 2 showed that effector-dependent sequence learning develops only when fingers of one hand are used, suggesting that effector-dependent sequence learning involves adjustment to the mechanical interactions between the fingers of one hand. In addition, when sequences had been practiced with one hand, mirror versions of the practiced sequences in both experiments showed moderate transfer. But when practiced with two hands no transfer to a mirrored version of the sequence was observed. This suggests that only practice with one hand produces a representation that facilitates the execution of mirror sequences. Generally, the same results were found in more or less aware participants, congruent with the idea that the effector-dependent representation and the representation allowing transfer to mirror sequences are implicit.

Automatic Keypress Activation in Skilled Typing

The assumption that letters automatically activate corresponding keypresses in skilled typing was investigated. Participants responded to the color of letters (congruent condition: responding finger was the one usually used to type the letter). Participants skilled in typing showed a congruency effect: unskilled participants did not (Experiment 1). The automatic activation included characteristics of the movement usually performed to type the letters (Experiment 2). Responding with crossed hands on an external response device (Experiment 3) provided evidence for effector-dependent representations only, whereas responding on a keyhoard (Experiment 4) resulted in evidence for effector-dependent and spatial representations. Thus, motoric skill proficiency is accompanied by automatic activation processes that probably contribute to high performance levels.