PMC

G1(0), Group 1 without delay; G2(0), Group 2 without delay; G3(0), Group 3 without delay; G3 70, Group 3 with delay of 70 ms; G3 100, Group 3 with delay of 100 ms; G3 150, Group 3 with delay of 150 ms; G3 200, Group 3 with delay of 200 ms; and G3 300, Group 3 with delay of 300 ms.

The hatch delay situation after long-term Cr(VI) exposure in marine medaka offspring. (A,B) hatch delay rate; (A) the hatch delay rate of offspring under different Cr(VI) treatment, different letter means the significant differences among different treatment (upper letter: p ≤ 0.01, lower letter: p ≤ 0.05); (B) the daily hatch delay rate under different offspring Cr(VI) exposure after parental Cr(VI) exposure, X axis represents parental treatment, and Y axis represents daily hatch delay rate, the blank line represents offspring in control environment, the red line represents offspring in Cr(VI) environment; the function relationships between exposure time and hatch delay rate were y = 0.41767x + 75.92824, R² = 0.06479 (untreated offspring) and y = 0.60299x + 76.06081, R² = 0.2451 (treated offspring); (C–F) hatch delay time; (C) the hatch delay time of offspring under different Cr(VI) treatment, different upper case means the significant differences among different treatment (p ≤ 0.01); different letter means the significant differences among different treatment (upper letter: p ≤ 0.01, lower letter: p ≤ 0.05) (D) the interaction of parent and offspring Cr(VI) treatment for hatch delay time (p = 0.028); (C,D), daily hatch delay time under different offspring Cr(VI) exposure after parental Cr(VI) exposure; (E) parental Cr(VI) exposure for first month, the function relationships between exposure time and hatch delay time were y = 007303x + 6.60125, R² = −0.0685 (untreated offspring) and y = −0.27692x + 13.00838, R² = 0.04457 (treated offspring); (F) parental Cr(VI) exposure for 2nd month, the function relationships between exposure time and hatch rate were y = −0.81409x + 47.69364, R² = 0.92974 (untreated offspring) and y =−0.75x + 44.33333, R² = 0.92857 (treated offspring). The number of biological samples used for each group is as follow: con-con (N = 297), con-cr (N = 34), cr1-con (N = 70), cr1-cr (N = 70), cr2-con (N = 28), cr2-cr (N = 8).

Illustration of level-dependent group delay for normal and impaired ears. Left: Impulse responses of filters in the normal (top panel) and impaired (bottom panel) periphery. The impulse response of the filter depends on how sharply tuned the filter is (filter functions shown at the right). Broad filters have a short build-up time, whereas sharp filters have a long build-up time. The build-up time is proportional to the group delay; the vertical lines show the group-delay approximation for gammatone filters used in the SPC system. In the normal ear, the group delay constantly fluctuates between the low- and high-SPL group-delay values (see arrow labeled dynamic group delay). In the impaired ear, the group delay varies much less across SPLs (vertical lines are closer to each other). However, by adding a dynamic delay (SPC), the normal dynamic group delay can be approximated on the output of the impaired filter.

Experimental protocols. In all experiments, the participants’ hand (gray) was hidden from sight the entire time. a, Experiment 1: Delay versus Control, transfer to reaching. Sessions alternated between a pong game and a reaching task. During a reach trial, a target (gray square) appeared in one of three locations in space beyond a start location (black square), and participants were asked to reach and stop at the target. An experiment started with a Reach – Training session in which participants received full visual feedback of the hand location using a cursor on the screen (dark gray filled square). After training, participants were presented with a Pong game session (No Delay), in which the paddle moved instantaneously with their hand movement, followed by a Blind Reach session where no visual feedback was provided at any point during the trial (Post No Delay, blue frame). The second Pong game session (Delay) was introduced with a delay (Delay group) or without a delay (Control group) between hand and paddle movements, and was followed by another Blind Reach session (Post Delay, orange frame). b, Experiment 2: Abrupt versus Gradual delay, transfer to reaching. The experimental protocol was similar to experiment 1, but with the addition of a Blind Reach – Training session: the cursor was omitted during movement, but was displayed at the movement stop location. In the second Pong game session, we introduced either an abruptly (Abrupt group) or gradually (Gradual group) increasing delay. c, Experiment 3: Abrupt versus Gradual delay, transfer to tracking (figure-eight). Sessions alternated between a pong game and a tracking task. During a track trial, participants were asked to track a target that moved along a figure-eight path (dashed gray). The path was not presented to the participants in a direction illustrated by the dotted dark gray arrow. The experiment started with a Track – Training session in which participants received full visual feedback on their hand location (dark gray filled square). After training, participants were presented with a Pong game session with no delay (No Delay), followed by a Blind Track session (Post No Delay, purple frame). Next, a Pong game session was introduced with either an abruptly (Abrupt group) or gradually (Gradual group) increasing delay (Delay), and was followed by another Blind Track session (Post Delay, green frame). d, Experiment 4: Gradual delay, transfer to tracking (mixture of sinusoids). Sessions alternated between a pong game and a tracking task. During a track trial, participants were asked to track a target that moved along a sagittal path (dashed gray). The path was not presented to the participants. The target trajectory (left zooming window) was designed as a mixture of five sinusoids of different frequencies and phases. The experiment started with a Track – Training session in which participants received full visual feedback on their hand location (dark gray filled square), followed by a Blind Track – Training session. After training, participants were presented with a Pong game session with no delay (No Delay), followed by a Blind Track session (Post No Delay, magenta frame). Next, a Pong game session was introduced with a gradually increasing delay (Delay), and was followed by another Blind Track session (Post Delay, cyan frame).