Error "Too many ('s." when trying to run a script with foreach loops

Question

My code is as follow:

#!/bin/tcsh

# Set relevant dataset information to be preprocessed
set subj = 20284
set date = 20230718 # YYYYMMDD

foreach run (001 002)
    set dataset = "${subj}_${date}_${run}.ds"

    cd /path/name/${subj}

    # Define your marker pairs and corresponding output file names
    set marker_pairs = (
        ("t104_noTap_R_antiphaseSlow", "t134_noTap_L_antiphaseSlow"),
        ("t114_noTap_R_antiphaseMedium", "t144_noTap_L_antiphaseMedium"),
        ("t124_noTap_R_antiphaseFast", "t154_noTap_R_antiphaseFast")
    )

    # Iterate through the marker pairs
    foreach pair ($marker_pairs)
        set marker1 = $pair[1]
        set marker2 = $pair[2]

        # Extract the part of the name in marker1 after "noTap_"
        set extracted_name = `echo $marker1 | sed 's/^.*_//g'`

        # Execute the first two scanMarkers commands and save their output to temporary files
        set output1 = "R_${extracted_name}_${run}_begin"
        set output2 = "L_${extracted_name}_${run}_begin"

        scanMarkers -f -includeBad -marker $marker1 -overlap 0 -time 0 0 -excludeEvent1 $marker1 -2.1 -0.1 -add $output1 $dataset "R_${extracted_name}_epoch_begintimes.evt"
        scanMarkers -f -includeBad -marker $marker2 -overlap 0 -time 0 0 -excludeEvent1 $marker2 -2.1 -0.1 -add $output2 $dataset "L_${extracted_name}_epoch_begintimes.evt"

        # Combine the outputs of the first two scanMarkers commands into one
        scanMarkers -f -includeBad -marker "${output1} ${output2}" -overlap 0 -time 0 0 -add "${extracted_name}_${run}_begin" $dataset "${extracted_name}_${run}_epoch_begintimes.evt"

        # Clean up the temporary files if needed
        rm -f "R_${extracted_name}_epoch_begintimes.evt" "L_${extracted_name}_epoch_begintimes.evt"
    end

    set options = ("antiphaseSlow" "antiphaseMedium" "antiphaseFast")

    foreach option ($options)
        set input_file = "${option}_${run}_epoch_begintimes.evt"
        set output_file = "${option}_${run}_1sec_times.prn"
        python /auto/iduna/arogojin/bilateral_squeeze_test/test_make_epoch_times_1sec.py "$input_file" "$output_file"
    end

    addMarker -f -n ${extracted_name}_${run}_1sec -p "$output_file" ${dataset}
end

The scanMarkers and addMarkers are functions in software I am using. I'm trying to see this up to iterate through multiple marker pairs (defined above). However, when I try to run the code as it is, I get the error: Too many ('s.