Predictive coding theorizes the capacity of neural structures to form predictions about forthcoming sensory events based on previous sensory input. This concept increasingly gains attention within experimental psychology and cognitive neuroscience. In auditory research, predictive coding has become a useful model that elegantly explains different aspects of auditory sensory processing and auditory perception. Many of these aspects are backed up by experimental evidence. However, certain fundamental features of predictive auditory processing have not been addressed so far by experimental investigations, like correlates of neural predictions that show up before the onset of an expected event. Four experiments were designed to investigate the proposed mechanism under more realistic conditions as compared to previous studies by manipulating different aspects of predictive (un)certainty, thereby examining the ecological validity of predictive processing in audition. Moreover, predictive certainty was manipulated gradually across five conditions from unpredictable to fully predictable in linearly increasing steps which drastically decreases the risk of discovering incidental findings. The results obtained from the conducted experiments partly confirm the results from previous studies by demonstrating effects of predictive certainty on ERPs in response to omissions of potentially predictable stimuli. Furthermore, results partly suggest that the auditory system actively engages in stimulus predictions in a literal sense as evidenced by gradual modulations of pre-stimulus ERPs associated with different degrees of predictive certainty. However, the current results remain inconsistent because the observed effects were relatively small and could not consistently be replicated in all follow-up experiments. The observed effects could be regained after accumulating the data across all experiments in order to increase statistical power. However, certain questions remain unanswered regarding a valid interpretation of the results in terms of predictive coding. Based on the current state of results, recommendations for future investigations are provided at the end of the current thesis in order to improve certain methodological aspects of investigating predictive coding in audition, including considerations on the design of experiments, possible suitable measures to investigate predictive coding in audition, recommendations for data acquisition and data analysis as well as recommendations for publication of results.

Predictive coding theorizes the capacity of neural structures to form predictions about forthcoming sensory events based on previous sensory input. This concept increasingly gains attention within experimental psychology and cognitive neuroscience. In auditory research, predictive coding has become a useful model that elegantly explains different aspects of auditory sensory processing and auditory perception. Many of these aspects are backed up by experimental evidence. However, certain fundamental features of predictive auditory processing have not been addressed so far by experimental investigations, like correlates of neural predictions that show up before the onset of an expected event. Four experiments were designed to investigate the proposed mechanism under more realistic conditions as compared to previous studies by manipulating different aspects of predictive (un)certainty, thereby examining the ecological validity of predictive processing in audition. Moreover, predictive certainty was manipulated gradually across five conditions from unpredictable to fully predictable in linearly increasing steps which drastically decreases the risk of discovering incidental findings. The results obtained from the conducted experiments partly confirm the results from previous studies by demonstrating effects of predictive certainty on ERPs in response to omissions of potentially predictable stimuli. Furthermore, results partly suggest that the auditory system actively engages in stimulus predictions in a literal sense as evidenced by gradual modulations of pre-stimulus ERPs associated with different degrees of predictive certainty. However, the current results remain inconsistent because the observed effects were relatively small and could not consistently be replicated in all follow-up experiments. The observed effects could be regained after accumulating the data across all experiments in order to increase statistical power. However, certain questions remain unanswered regarding a valid interpretation of the results in terms of predictive coding. Based on the current state of results, recommendations for future investigations are provided at the end of the current thesis in order to improve certain methodological aspects of investigating predictive coding in audition, including considerations on the design of experiments, possible suitable measures to investigate predictive coding in audition, recommendations for data acquisition and data analysis as well as recommendations for publication of results.:1. Introduction ... 5 1.1 An introduction to predictive coding theory ... 9 1.2 Predictive coding in audition ... 11 1.3 Electrophysiological correlates of predictive auditory processing ... 14 1.4 Limitations of previous research and aims of the thesis ... 21 2. Traditional correlates of auditory prediction ... 24 2.1 Experiment 1: Reliability of auditory predictions ... 25 2.2 Experiment 2: Accuracy of auditory predictions ... 39 3. Pre-stimulus correlates of auditory prediction ...47 3.1 Pre-stimulus effects in Experiment 1 and 2 ... 48 3.2 Experiment 3: Temporal dynamics of auditory prediction ... 56 3.3 Experiment 4: The influence of omissions on stimulus processing ... 64 4 Results across experiments ... 74 4.1 Methods ... 76 4.2 Results ... 80 4.3 Discussion ... 82 5. General Discussion ... 87 5.1 Implications for current research ... 89 5.2 Recommendations for future investigations ... 93 5.3 Future prospects ... 101 5.4 Conclusion ... 104 References ...106 Appendix ... 116

Traditionellt utvärderas effekter av kognitiv träning med objektiva prestationsmått. Syftet med uppsatsen var att undersöka självskattad exekutiv funktion som ett alternativt mått för att utvärdera effekter av kognitiv träning. Som utfallsmått valdes The behavior rating inventory of executive functioning - self report (BRIEF-SR). Vidare användes blandad design med för- och eftermätning samt tre oberoende grupper. Gymnasieelever (n = 63) delades in i; aktiv träningsgrupp, aktiv placebogrupp och passiv kontrollgrupp. Tränings- och placebogruppen genomförde datoriserad kognitiv träning med respektive utan adaptiv svårighetsgrad. ANCOVA med arbetsminneskapacitet som kovariat visade inga signifikanta träningseffekter på självskattade exekutiva funktioner, oavsett grupptillhörighet. Sammantaget kan BRIEF-SR vara ett lämpligt instrument vid utvärdering av kognitiv träning när ekologisk validitet prioriteras. Resultaten diskuteras avseende inverkan av tid mellan för- och eftermätning, population och förväntanseffekter. / Performance based measures have been the Golden standard when evaluating effects of cognitive training. By using The Behavior Rating Inventory of Executive Functioning-Self Report (BRIEF-SR), this thesis aimed to explore self- rating scales as an alternative when evaluating effects of cognitive training. A sample of high school students (n = 63) and a mixed- effect model with pre- and post-measurements were chosen. The students were divided into three groups: active training, training with placebo or passive control. The two groups in training practiced with a computerized cognitive training program. The two training groups practiced with an adaptive and non-adaptive computer program, respectively.  With working memory as covariate ANCOVA reported no significant effects on self-rated executive functions independent of group condition. In sum, if ecological validity is of priority BRIEF-SR can be considered when measuring effects following cognitive training. In addition the results are discussed with regards to time between pre- and post-measurements, population and effects of expectancy. / Effekter av kognitiv träning på skolprestationer och självreglering av beteende (dnr 1,2009/0 018,5-0)